1.
Ayers Rock (band)
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Ayers Rock were an Australian jazz fusion, progressive rock band which formed in August 1973. Ray Burton, Mark Kennedy, and Duncan McGuire, members of Leo de Castro and Friends, left to form the trio of Burton. They added a guitarist, Jimmy Doyle, changed their name to Ayers Rock, the group signed with independent label Mushroom Records in December 1973. Burton left the following March, and was replaced by Chris Brown, the bands first album, Big Red Rock, received positive reviews and peaked at number 32 on the Australian Kent Music Report album chart. It featured mainstream rock and three longer, instrumental tracks which introduced progressive styles, including jazz fusion, label owner Michael Gudinski promoted Ayers Rock in Los Angeles and they signed with A&M Records, the first Mushroom Records artists to sign with an international label. The United States release of Big Red Rock in February 1975 was followed by a tour there, the band played to large crowds, supporting major international artists before 35,000 people – the first Australian band to perform in large US stadiums. Ayers Rock were named 1975 Musicians of the Year on RAMs New Years Honors List, Kennedy left before their second album, Beyond, was released. The album blended a number of genres and had a positive critical reception. The band toured the US again, Loughnan remained there, a year later Doyle and Brown recruited members for a new lineup, including Andy Cowan and Hamish Stuart. In 1980 they released their album, Hotspell, on their own Red Rock Records label. This album had a style, with sophisticated arrangements and featured keyboards. It failed to chart, and the group disbanded in 1981. Although Ayers Rocks first two albums were successful in Australia, none of their six singles charted, during their early years, the group were praised by local media for their music, stylistic diversity, use of technology, and the energy of their live performances. Ayers Rock received positive reviews in Billboard and Cashbox, late-1990s music historians recognised the bands talent but considered their music over-indulgent at times, failing to bridge the gap between artistic and commercial success. Duncan Kimball of Milesago. com wrote that never really got the chance to reach their full potential. Ayers Rock were formed in the Australian pop-music scene of the early 1970s, which included artists in a number of genres, mainstream pop, blues rock, heavy rock, bands such as Blackfeather and Madder Lake combined mainstream and progressive rock. Most pop and rock listeners had never heard jazz fusion, when Ayers Rock incorporated the music into their sets, at that time, the Australian music media expressed frustration that few local musicians were successful overseas. Many artists had gone to the United Kingdom with little commercial success, the third wave of Australian rock, from 1970 to 1975, saw an increase in pub rock venues in the southern and eastern states
Ayers Rock (band)
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Ayers Rock performing at the Australian Concert for Bangladesh, April 1975. L to R: Chris Brown, Duncan McGuire, Mark Kennedy, Jimmy Doyle, and Col Loughnan.
Ayers Rock (band)
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Jimmy Doyle founding mainstay guitarist of Ayers Rock, 1981.
Ayers Rock (band)
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Mark Kennedy of Ayers Rock (1973–76), during a recording session at the Record Plant, L.A. in September 1975.
Ayers Rock (band)
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Duncan McGuire (left) and Chris Brown at the Record Plant, L.A. in September 1975.
2.
Australia
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Australia, officially the Commonwealth of Australia, is a country comprising the mainland of the Australian continent, the island of Tasmania and numerous smaller islands. It is the worlds sixth-largest country by total area, the neighbouring countries are Papua New Guinea, Indonesia and East Timor to the north, the Solomon Islands and Vanuatu to the north-east, and New Zealand to the south-east. Australias capital is Canberra, and its largest urban area is Sydney, for about 50,000 years before the first British settlement in the late 18th century, Australia was inhabited by indigenous Australians, who spoke languages classifiable into roughly 250 groups. The population grew steadily in subsequent decades, and by the 1850s most of the continent had been explored, on 1 January 1901, the six colonies federated, forming the Commonwealth of Australia. Australia has since maintained a liberal democratic political system that functions as a federal parliamentary constitutional monarchy comprising six states. The population of 24 million is highly urbanised and heavily concentrated on the eastern seaboard, Australia has the worlds 13th-largest economy and ninth-highest per capita income. With the second-highest human development index globally, the country highly in quality of life, health, education, economic freedom. The name Australia is derived from the Latin Terra Australis a name used for putative lands in the southern hemisphere since ancient times, the Dutch adjectival form Australische was used in a Dutch book in Batavia in 1638, to refer to the newly discovered lands to the south. On 12 December 1817, Macquarie recommended to the Colonial Office that it be formally adopted, in 1824, the Admiralty agreed that the continent should be known officially as Australia. The first official published use of the term Australia came with the 1830 publication of The Australia Directory and these first inhabitants may have been ancestors of modern Indigenous Australians. The Torres Strait Islanders, ethnically Melanesian, were originally horticulturists, the northern coasts and waters of Australia were visited sporadically by fishermen from Maritime Southeast Asia. The first recorded European sighting of the Australian mainland, and the first recorded European landfall on the Australian continent, are attributed to the Dutch. The first ship and crew to chart the Australian coast and meet with Aboriginal people was the Duyfken captained by Dutch navigator, Willem Janszoon. He sighted the coast of Cape York Peninsula in early 1606, the Dutch charted the whole of the western and northern coastlines and named the island continent New Holland during the 17th century, but made no attempt at settlement. William Dampier, an English explorer and privateer, landed on the north-west coast of New Holland in 1688, in 1770, James Cook sailed along and mapped the east coast, which he named New South Wales and claimed for Great Britain. The first settlement led to the foundation of Sydney, and the exploration, a British settlement was established in Van Diemens Land, now known as Tasmania, in 1803, and it became a separate colony in 1825. The United Kingdom formally claimed the part of Western Australia in 1828. Separate colonies were carved from parts of New South Wales, South Australia in 1836, Victoria in 1851, the Northern Territory was founded in 1911 when it was excised from South Australia
Australia
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Aboriginal rock art in the
Kimberley region of Western Australia
Australia
Australia
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Portrait of Captain
James Cook, the first European to map the eastern coastline of Australia in 1770
Australia
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Tasmania's
Port Arthur penal settlement is one of eleven UNESCO World Heritage-listed
Australian Convict Sites.
3.
Northern Territory
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The Northern Territory is a federal Australian territory in the central and central northern regions of Australia. It shares borders with Western Australia to the west, South Australia to the south, to the north, the territory is bordered by the Timor Sea, the Arafura Sea and the Gulf of Carpentaria. Despite its large area—over 1,349,129 square kilometres, the Northern Territorys population of 244,000 makes it the least populous of Australias eight major states and territories, having fewer than half as many people as Tasmania. The archaeological history of the Northern Territory begins over 40,000 years ago when Indigenous Australians settled the region, makassan traders began trading with the indigenous people of the Northern Territory for trepang from at least the 18th century onwards. The coast of the territory was first seen by Europeans in the 17th century, the British were the first Europeans to attempt to settle the coastal regions. After three failed attempts to establish a settlement, success was achieved in 1869 with the establishment of a settlement at Port Darwin. Today the economy is based on tourism, especially Kakadu National Park in the Top End and the Uluru-Kata Tjuta National Park in central Australia, the capital and largest city is Darwin. The population is not concentrated in regions but rather along the Stuart Highway. The other major settlements are Palmerston, Alice Springs, Katherine, Nhulunbuy, residents of the Northern Territory are often known simply as Territorians and fully as Northern Territorians, or more informally as Top Enders and Centralians. With the coming of the British, there were four attempts to settle the harsh environment of the northern coast. The Northern Territory was part of colonial New South Wales from 1825 to 1863, except for a time from February to December 1846. It was part of South Australia from 1863 to 1911, under the administration of colonial South Australia, the overland telegraph was constructed between 1870 and 1872. A railway was built between Palmerston and Pine Creek between 1883 and 1889. The economic pattern of raising and mining was established so that by 1911 there were 513,000 cattle. Victoria River Downs was at one time the largest cattle station in the world, gold was found at Grove Hill in 1872 and at Pine Creek, Brocks Creek, Burrundi, and copper was found at Daly River. On 1 January 1911, a decade after federation, the Northern Territory was separated from South Australia, alfred Deakin opined at this time To me the question has been not so much commercial as national, first, second, third and last. Either we must accomplish the peopling of the territory or submit to its transfer to some other nation. In late 1912 there was growing sentiment that the name Northern Territory was unsatisfactory, the names Kingsland, Centralia and Territoria were proposed with Kingsland becoming the preferred choice in 1913
Northern Territory
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Thomas Baines with Aborigines near the mouth of the
Victoria River.
Northern Territory
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Flag
Northern Territory
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Letters Patent annexing the Northern Territory to South Australia, 1863
Northern Territory
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The northern coast of Australia is on the left with Melville Island in the lower right.
4.
Geographic coordinate system
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A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols. The coordinates are chosen such that one of the numbers represents a vertical position. A common choice of coordinates is latitude, longitude and elevation, to specify a location on a two-dimensional map requires a map projection. The invention of a coordinate system is generally credited to Eratosthenes of Cyrene. Ptolemy credited him with the adoption of longitude and latitude. Ptolemys 2nd-century Geography used the prime meridian but measured latitude from the equator instead. Mathematical cartography resumed in Europe following Maximus Planudes recovery of Ptolemys text a little before 1300, in 1884, the United States hosted the International Meridian Conference, attended by representatives from twenty-five nations. Twenty-two of them agreed to adopt the longitude of the Royal Observatory in Greenwich, the Dominican Republic voted against the motion, while France and Brazil abstained. France adopted Greenwich Mean Time in place of local determinations by the Paris Observatory in 1911, the latitude of a point on Earths surface is the angle between the equatorial plane and the straight line that passes through that point and through the center of the Earth. Lines joining points of the same latitude trace circles on the surface of Earth called parallels, as they are parallel to the equator, the north pole is 90° N, the south pole is 90° S. The 0° parallel of latitude is designated the equator, the plane of all geographic coordinate systems. The equator divides the globe into Northern and Southern Hemispheres, the longitude of a point on Earths surface is the angle east or west of a reference meridian to another meridian that passes through that point. All meridians are halves of great ellipses, which converge at the north and south poles, the prime meridian determines the proper Eastern and Western Hemispheres, although maps often divide these hemispheres further west in order to keep the Old World on a single side. The antipodal meridian of Greenwich is both 180°W and 180°E, the combination of these two components specifies the position of any location on the surface of Earth, without consideration of altitude or depth. The grid formed by lines of latitude and longitude is known as a graticule, the origin/zero point of this system is located in the Gulf of Guinea about 625 km south of Tema, Ghana. To completely specify a location of a feature on, in, or above Earth. Earth is not a sphere, but a shape approximating a biaxial ellipsoid. It is nearly spherical, but has an equatorial bulge making the radius at the equator about 0. 3% larger than the radius measured through the poles, the shorter axis approximately coincides with the axis of rotation
Geographic coordinate system
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Longitude lines are perpendicular and latitude lines are parallel to the equator.
5.
Arkose
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Arkose is a detrital sedimentary rock, specifically a type of sandstone containing at least 25% feldspar. Arkosic sand is sand that is rich in feldspar. Quartz is commonly the dominant mineral component, and some mica is often present, apart from the mineral content, rock fragments may also be a significant component. Arkose usually contains small amounts of cement, which causes it to fizz slightly in dilute hydrochloric acid. Arkose is typically grey to reddish in colour, the sand grains making up an arkose may range from fine to very coarse, but tend toward the coarser end of the scale. Fossils are rare in arkose, due to the processes that form it. Arkose is generally formed from the weathering of feldspar-rich igneous or metamorphic, most commonly granitic rocks, arkose is often associated with conglomerate deposits sourced from granitic terrain and is often found above unconformities in the immediate vicinity of granite terrains. The central Australian monolith Uluru is composed of late Neoproterozoic/Cambrian arkose, deposited in the Amadeus Basin
Arkose
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Arkosic sand in the
Llano Uplift, Texas, U.S., with
granite outcrops
Arkose
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Grus sand and the granitoid it is derived from
Arkose
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Arkose sandstone found in
Slovakia
6.
Petermann Orogeny
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The Petermann Orogeny was an Australian intracontinental event that affected basement rocks of the northern Musgrave Province and Ediacaran sediments of the southern Amadeus Basin between ~550-535 Ma. The remains are today in the Petermann Ranges. Prior to the Petermann Orogeny, which resulted in exhumation of the Musgrave Block, the extent and effect of the Petermann Orogen appears to be relatively confined, occurring most pervasively within the central northern-Musgrave Block. Here, older Musgravian fabrics are partially to completely overprinted by sub-eclogite-facies mineral assemblages, the Woodroofe Thrust, Davenport Shear Zone and Mann Fault accommodated much of the 30–40 km exhumation. Beyond this region of intense Petermann-aged activity, deformation related to the Petermann Orogen is less pervasive, sedimentation associated with the Petermann Orogeny is responsible for the deposition of the Georgina Basin, Officer Basin, Ngalia Basin and Amadeus Basin sediments in the Cambrian. Sediments are a mixture of fluvial conglomerates, sandstones, and siltstones, several pull-apart structural grabens formed at flexures in the orogenic belt, forming the Levenger and Moorilyanna Grabens. The Petermann Orogeny is dominated by south-over-north movement on several large, the prime thrust fault is the Woodroffe Thrust, which is a laminated pseudotachlyte-schist zone up to 300 metres thick. This has accommodated up to 42 kilometres of movement at an angle of about 15 to 20 degrees. Six deformations are known Folds of D1, D2 and D3 rare, D4 isoclinal upright, megascale Z folding of unknown provenance correlates with NE trending Mundrabilla Lineament parallel structures, and is probably D2 or D3. Foliations associated with the Petermann Orogeny are typically steeply to gently south-dipping, the tectonics of the Petermann Orogeny are extremely unusual, as it occurred in an intraplate setting in the centre of the Australian continental block. Problems with this include lack of geochronology, and general lack of kinematics directly linked to transpression. This is envisaged as a kind of feedback loop between sedimentation and isostatic orogenic events, however, some authors have called this into question with isotopic models. The Petermann Orogeny exposes deep crustal roots of the previous Musgrave Orogen and lkely parts of several poorly exposed Proterozoic orogenic belts, as such, the rocks of the Petermann Orogen are considered prospective territory for mineral exploration. The history of exploration in the Petermann Orogen extends back to the last half of the 19th century, with a series of prospectors. Most famously was Lasseter, who allegedly found Lasseters Reef, a near-mythical gold lode of such richness and scale that it has fired imaginations for over a century, but remains undiscovered. The advent of the Mabo Decision and land rights movements has seen aboriginal land rights improved, with the result that they now control access to land and this has created uncertainty about tenure and land access for mineral exploration. Podiform copper hosted in sheared basalts in the Warburton Ranges, near Warburton, Western Australia, exploration for Olympic Dam lookalikes and for magmatic nickel copper mineralisation is continuing. There are only one or two geology oriented documentaries that trace Uluru and Kata Tjutas origins with the Australian Petermann Ranges, the Time Travellers Guide To Australia in 2012 is possibly the first documentary to make the connection with reasonable clarity
Petermann Orogeny
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Geological interpretation of the West Musgrave Block, Western Australia. 50x50km grid for scale.
7.
World Heritage Site
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A World Heritage Site is a landmark which has been officially recognized by the United Nations, specifically by the United Nations Educational, Scientific and Cultural Organization. Sites are selected on the basis of having cultural, historical, scientific or some form of significance. UNESCO regards these sites as being important to the interests of humanity. The programme catalogues, names, and conserves sites of outstanding cultural or natural importance to the common culture, under certain conditions, listed sites can obtain funds from the World Heritage Fund. The program was founded with the Convention Concerning the Protection of the Worlds Cultural and Natural Heritage, since then,192 state parties have ratified the convention, making it one of the most adhered to international instruments. As of July 2016,1052 sites are listed,814 cultural,203 natural, in 1959, the governments of Egypt and Sudan requested UNESCO to assist their countries to protect and rescue the endangered monuments and sites. In 1960, the Director-General of UNESCO launched an appeal to the Member States for an International Campaign to Save the Monuments of Nubia, the campaign, which ended in 1980, was considered a success. The project cost $80 million, about $40 million of which was collected from 50 countries, the projects success led to other safeguarding campaigns, saving Venice and its lagoon in Italy, the ruins of Mohenjo-daro in Pakistan, and the Borobodur Temple Compounds in Indonesia. UNESCO then initiated, with the International Council on Monuments and Sites, the United States initiated the idea of cultural conservation with nature conservation. The International Union for Conservation of Nature developed similar proposals in 1968, the Convention came into force on 17 December 1975. As of June 2016, it has been ratified by 192 states, including 188 UN member states plus the Cook Islands, the Holy See, Niue, a country must first list its significant cultural and natural sites, the result is called the Tentative List. A country may not nominate sites that have not been first included on the Tentative List, next, it can place sites selected from that list into a Nomination File. The Nomination File is evaluated by the International Council on Monuments and Sites and these bodies then make their recommendations to the World Heritage Committee. There are ten selection criteria – a site must meet at least one of them to be included on the list, up to 2004, there were six criteria for cultural heritage and four criteria for natural heritage. In 2005, this was modified so there is now only one set of ten criteria. Nominated sites must be of outstanding value and meet at least one of the ten criteria. Thus, the Geneva Convention treaty promulgates, Article 53, PROTECTION OF CULTURAL OBJECTS AND OF PLACES OF WORSHIP. There are 1,052 World Heritage Sites located in 165 States Party, of these,814 are cultural,203 are natural and 35 are mixed properties
World Heritage Site
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Site #252:
Taj Mahal, an example of cultural heritage site
World Heritage Site
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Logo of the
United Nations Educational, Scientific and Cultural Organization (UNESCO)
World Heritage Committee
World Heritage Site
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Site #156:
Serengeti National Park, an example of natural heritage site
World Heritage Site
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Site #274:
Historic Sanctuary of Machu Picchu, an example of mixed heritage site
8.
Sandstone
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Sandstone is a clastic sedimentary rock composed mainly of sand-sized minerals or rock grains. Most sandstone is composed of quartz or feldspar because these are the most common minerals in the Earths crust, like sand, sandstone may be any color, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, quartz-bearing sandstone is converted into quartzite through heating and pressure, usually related to tectonic compression within orogenic belts. They are formed from cemented grains that may either be fragments of a rock or be mono-minerallic crystals. The cements binding these grains together are typically calcite, clays, grain sizes in sands are defined within the range of 0.0625 mm to 2 mm. The formation of sandstone involves two principal stages, first, a layer or layers of sand accumulates as the result of sedimentation, either from water or from air. Typically, sedimentation occurs by the settling out from suspension. The most common cementing materials are silica and calcium carbonate, which are derived either from dissolution or from alteration of the sand after it was buried. Colours will usually be tan or yellow, a predominant additional colourant in the southwestern United States is iron oxide, which imparts reddish tints ranging from pink to dark red, with additional manganese imparting a purplish hue. Red sandstones are seen in the Southwest and West of Britain, as well as central Europe. The regularity of the latter favours use as a source for masonry, either as a building material or as a facing stone. These physical properties allow the grains to survive multiple recycling events. Quartz grains evolve from rock, which are felsic in origin. Feldspathic framework grains are commonly the second most abundant mineral in sandstones, Feldspar can be divided into two smaller subdivisions, alkali feldspars and plagioclase feldspars. The different types of feldspar can be distinguished under a petrographic microscope, below is a description of the different types of feldspar. Alkali feldspar is a group of minerals in which the composition of the mineral can range from KAlSi3O8 to NaAlSi3O8. Plagioclase feldspar is a group of solid solution minerals that range in composition from NaAlSi3O8 to CaAl2Si2O8. Lithic framework grains are pieces of ancient source rock that have yet to weather away to individual mineral grains, accessory minerals are all other mineral grains in a sandstone, commonly these minerals make up just a small percentage of the grains in a sandstone
Sandstone
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Cut slab of sandstone showing
Liesegang banding
Sandstone
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Devonian Sandstone at Suur Taevaskoda,
Põlva County,
Estonia
Sandstone
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Alcove in the
Navajo Sandstone
Sandstone
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Sandstone Rock-cut tombs (
Kokhim) in
Petra,
Jordan
9.
Alice Springs
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Alice Springs /ˌælᵻs ˈsprɪŋz/ is the third largest town in the Northern Territory of Australia. Popularly known as the Alice or simply Alice, Alice Springs is situated roughly in Australias geographic centre. The area is known as Mparntwe to its inhabitants, the Arrernte. The name Alice Springs was given by surveyor William Whitfield Mills after Lady Alice Todd, Alice Springs has a population of 27,972, which makes up 8.7 percent of the territorys population. Alice Springs is nearly equidistant from Adelaide and Darwin, the town straddles the usually dry Todd River on the northern side of the MacDonnell Ranges. The surrounding region is known as Central Australia, or the Red Centre, the Aboriginal name for Alice Springs is Mparntwe. Many Arrernte people also live in communities outside of Alice Springs, three major groups, the Western, Eastern and Central Arrernte people live in Central Australia, their traditional land including the area of Alice Springs and MacDonnell Ranges. They have also referred to as Aranda, Arrarnta, Arunta. There are five dialects of the Arrernte language, South-eastern, Central, Arrernte country is rich with mountain ranges, waterholes and gorges, which create a variety of natural habitats. The numerous sites of importance in and around Alice Springs include Anthwerrke, Akeyulerre, Ntaripe, Atnelkentyarliweke. A white settlement was started ten years later with the construction of a station on the Overland Telegraph Line. The OTL was completed in 1872 and it traced Stuarts route and opened up the interior for permanent settlement. The Alice Springs Telegraph Station was sited near what was thought to be a permanent waterhole in the normally dry Todd River, the settlement was optimistically named Alice Springs after the wife of the former Postmaster General of South Australia, Sir Charles Todd. The Todd River was named after Sir Charles and it was not until alluvial gold was discovered at Arltunga,100 kilometres east of the present Alice Springs, in 1887 that any significant European settlement occurred. The towns first substantial building was the Stuart Town Gaol in Parsons Street which was built in 1909 when the town had a European population of fewer than 20 people, many of the gaols first prisoners were first contact aboriginal men incarcerated for killing cattle. The first aircraft, piloted by Francis Stewart Briggs landed in 1921, Central Australias first hospital, Adelaide House, was built in 1926 when the European population of the town was about 40. It was not until 1929 when the line to Alice was built. Aboriginal Centralians outnumbered European Centralians until the mid-1930s, until 31 August 1933, the town was officially known as Stuart
Alice Springs
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View of Alice Springs CBD from Anzac Hill.
Alice Springs
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The "springs" that give the town its name
Alice Springs
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Telegraph station
Alice Springs
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Panorama of Alice Springs
10.
Pitjantjatjara
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The Pitjantjatjara are an Aboriginal people of the Central Australian desert. They are closely related to the Yankunytjatjara and Ngaanyatjarra and their languages are, to a large extent and they refer to themselves as Anangu. The land is an inseparable and important part of their identity, the name Pitjantjatjara derives from the word pitjantja, a form of the verb go which, combined with the comitative suffix -tjara means something like pitjantja-having. This distinguishes it from its near neighbour Yankunytjatjara which has yankunytja for the same meaning and this naming strategy is also the source of the names of Ngaanyatjarra and Ngaatjatjarra but in that case the names contrast the two languages based on their words for this. The two languages Pitjantjatjara and Yankunytjatjara may be grouped together under the name Nyangatjatjara which then contrasts them with Ngaanyatjarra and Ngaatjatjarra, the name Pitjantjatjara is usually pronounced with elision of one of the repeated syllables -tja-, thus, pitjantjara. In more careful speech all syllables will be pronounced, from 1950 onwards, many Anangu were forced to leave their homelands due to British nuclear tests at Maralinga. Some Anangu were subsequently contaminated by the fallout from the atomic tests. Their experience of issues of rights and native title in South Australia has been unique. The Maralinga Tjarutja Land Rights Act,1984 granted freehold title of an area of 80,764 square kilometres to Maralinga Tjarutja, the subsequently named Mamungari Conservation Park) with 21,357.8 km² was transferred to the Maralinga Tjarutja in 2004. Ayers Rock and The Olgas are separated from the Pitjantjatjara Lands by the border between the Northern Territory and South Australia and have become a major tourist attraction and a National Park. The Central Land Council laid claim to the Ayers-Rock-Mount Olga National Park and some adjoining vacant Crown land in 1979, but this claim was challenged by the Northern Territory government. After years of lobbying by the Land Council, on 11 November 1983. This was implemented in 1985, after further negotiations extended the period from 50 to 99 years. The Arrernte land is land in central Australia. It is controlled by Arrernte Council which in turn is controlled by Central Land Council from Alice Springs, wiltja, a shelter made by the Pitjantjatjara people and other indigenous Australian groups Duguid, Charles. New Revised edition of Pitjantjatjara texts, canberra, Australian Institute of Aboriginal Studies. The People in Between, The Pitjantjatjara People of Ernabella, minyma Tjuta Tjunguringkula Kunpuringanyi, Women Growing Strong Together. Ngaanyatjarra, Pitjantjatjara, Yankunytjatjara Womens Council 1980-1990, Growing Up the Country, The Pitjantjatjara struggle for their land
Pitjantjatjara
–
Pitjantjatjara people (
Anangu) live in the area around
Uluru and south to the
Great Australian Bight
Pitjantjatjara
–
Pitjantjatjara ranger at Uluru
11.
Indigenous Australians
–
Indigenous Australians are the Aboriginal and Torres Strait Islander people of Australia, descended from groups that existed in Australia and surrounding islands prior to European colonisation. In present-day Australia these groups are divided into local communities. At the time of initial European settlement, over 250 languages were spoken, it is estimated that 120 to 145 of these remain in use. Aboriginal people today mostly speak English, with Aboriginal phrases and words being added to create Australian Aboriginal English, a population collapse following European settlement, and a smallpox epidemic spreading three years after the arrival of Europeans may have caused a massive and early depopulation. Since 1995, the Australian Aboriginal Flag and the Torres Strait Islander Flag have been among the flags of Australia. The word aboriginal has been in the English language since at least the 16th century, to mean, first or earliest known and it comes from the Latin word aborigines, derived from ab and origo. The word was used in Australia to describe its indigenous peoples as early as 1789 and it soon became capitalised and employed as the common name to refer to all Indigenous Australians. Strictly speaking, Aborigine is the noun and Aboriginal the adjectival form, however, use of either Aborigine or Aboriginal to refer to individuals has acquired negative connotations in some sectors of the community, and it is generally regarded as insensitive and even offensive. The more acceptable and correct expression is Aboriginal Australians or Aboriginal people, the term Indigenous Australians, which also includes Torres Strait Islander peoples, has found increasing acceptance, particularly since the 1980s. The broad term Aboriginal Australians includes many groups that often identify under names from local Indigenous languages. Anindilyakwa on Groote Eylandt off Arnhem Land, Palawah in Tasmania and these larger groups may be further subdivided, for example, Anangu recognises localised subdivisions such as Pitjantjatjara, Yankunytjatjara, Ngaanyatjarra, Luritja and Antikirinya. It is estimated that prior to the arrival of British settlers, the Torres Strait Islanders possess a heritage and cultural history distinct from Aboriginal traditions. The eastern Torres Strait Islanders in particular are related to the Papuan peoples of New Guinea, accordingly, they are not generally included under the designation Aboriginal Australians. This has been another factor in the promotion of the inclusive term Indigenous Australians. Six percent of Indigenous Australians identify themselves fully as Torres Strait Islanders, a further 4% of Indigenous Australians identify themselves as having both Torres Strait Islander and Aboriginal heritage. The Torres Strait Islands comprise over 100 islands which were annexed by Queensland in 1879, eddie Mabo was from Mer or Murray Island in the Torres Strait, which the famous Mabo decision of 1992 involved. The term blacks has been used to refer to Indigenous Australians since European settlement, while originally related to skin colour, the term is used today to indicate Aboriginal heritage or culture in general and refers to people of any skin pigmentation. In the 1970s, many Aboriginal activists, such as Gary Foley, proudly embraced the term black, the book included interviews with several members of the Aboriginal community including Robert Jabanungga reflecting on contemporary Aboriginal culture
Indigenous Australians
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Men from
Bathurst Island, 1939
Indigenous Australians
Indigenous Australians
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Men and boys playing a game of gorri, 1922
Indigenous Australians
–
Artwork depicting the first contact that was made with the
Gweagal Aboriginal people and
Captain James Cook and his crew on the shores of the
Kurnell Peninsula, New South Wales
12.
Depression (geology)
–
A depression in geology is a landform sunken or depressed below the surrounding area. Erosion-related, Blowout, a depression created by wind erosion typically in either a partially vegetated sand dune ecosystem or dry soils, glacial valley, a depression carved by erosion by a glacier. River valley, a depression carved by erosion by a river. Area of subsidence caused by the collapse of a structure such as sinkholes in karst terrain. Sink, an endorheic depression generally containing a persistent or intermittent lake, collapse-related, Sinkhole, a depression formed as a result of the collapse of rocks lying above a hollow. This is common in karst regions, kettle, a shallow, sediment-filled body of water formed by melting glacial remnants in terminal moraines. Thermokarst hollow, caused by loss of the ground as the result of permafrost thawing. Impact-related, Impact crater, a depression created by an impact such as a meteorite crater, sedimentary-related, Sedimentary basin, in sedimentology, an area thickly filled with sediment in which the weight of the sediment further depresses the floor of the basin. Structural or tectonic-related, Structural basin, a depression, a region of tectonic downwarping as a result of isostasy or subduction. Graben or rift valley, fallen and typically linear depressions or basins created by rifting in a region under tensional tectonic forces, pull-apart basin caused by offset in a strike slip or transform fault. Oceanic trench, a linear depression on the ocean floor. Oceanic trenches are caused by subduction of oceanic crust beneath either oceanic crust or continental crust, pit crater, a volcanic depression smaller than a caldera formed by a sinking, or caving in, of the ground surface lying over a void. Maar, a resulting from phreatomagmatic eruption or diatreme explosion. Cryptodepression List of places on land with elevations below sea level
Depression (geology)
–
A watering hole is a depression where water collects and animals come to drink
13.
Cave painting
–
Cave paintings are painted drawings on cave walls or ceilings, mainly of prehistoric origin, to some 40,000 years ago in Eurasia. The exact purpose of the Paleolithic cave paintings is not known, evidence suggests that they were not merely decorations of living areas since the caves in which they have been found do not have signs of ongoing habitation. They are also located in areas of caves that are not easily accessible. Some theories hold that cave paintings may have been a way of communicating with others, the paintings are remarkably similar around the world, with animals being common subjects that give the most impressive images. Humans mainly appear as images of hands, mostly hand stencils made by blowing pigment on a hand held to the wall. The earliest known cave paintings/drawings of animals are at least 35,000 years old and are found in Pettakere cave on the island of Sulawesi in Indonesia, previously it was believed that the earliest paintings were in Europe. The earliest non-figurative rock art dates back to approximately 40,000 years ago, nearly 340 caves have now been discovered in France and Spain that contain art from prehistoric times. But subsequent technology has made it possible to date the paintings by sampling the pigment itself, the choice of subject matter can also indicate chronology. For instance, the reindeer depicted in the Spanish cave of Cueva de las Monedas places the drawings in the last Ice Age. The oldest date given to a cave painting is now a pig that has a minimum age of 35,400 years old at Pettakere cave in Sulawesi. Indonesian and Australian scientists have dated other non-figurative paintings on the walls to be approximately 40,000 years old, the method they used to confirm this was dating the age of the stalactites that formed over the top of the paintings. The art is similar in style and method to that of the Indonesian caves as there were also hand stencils and this date coincides with the earliest known evidence for Homo sapiens in Europe. Because of the cave arts age, some scientists have conjectured that the paintings may have made by Neanderthals. The earliest known European figurative cave paintings are those of Chauvet Cave in France and these paintings date to earlier than 30,000 BCE according to radiocarbon dating. Some researchers believe the drawings are too advanced for this era, the radiocarbon dates from these samples show that there were two periods of creation in Chauvet,35,000 years ago and 30,000 years ago. In 2009, cavers discovered drawings in Coliboaia Cave in Romania, an initial dating puts the age of an image in the same range as Chauvet, about 32,000 years old. Some caves probably continued to be painted over a period of thousands of years. This was created roughly between 10,000 and 5,500 years ago, and painted in rock shelters under cliffs or shallow caves, though individual figures are less naturalistic, they are grouped in coherent grouped compositions to a much greater degree
Cave painting
–
Cave of Altamira, near
Santander,
Spain.
Cave painting
–
Cueva de las Manos (Spanish for Cave of the Hands) in the Santa Cruz province in
Argentina
Cave painting
–
Cueva de las Monedas
Cave painting
–
Spanish cave painting of bulls.
14.
UNESCO
–
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations based in Paris. It is the heir of the League of Nations International Committee on Intellectual Cooperation, UNESCO has 195 member states and nine associate members. Most of its offices are cluster offices covering three or more countries, national and regional offices also exist. UNESCO pursues its objectives through five major programs, education, natural sciences, social/human sciences, culture and it is also a member of the United Nations Development Group. UNESCO and its mandate for international cooperation can be traced back to a League of Nations resolution on 21 September 1921, on 18 December 1925, the International Bureau of Education began work as a non-governmental organization in the service of international educational development. However, the work of predecessor organizations was largely interrupted by the onset of World War II. On 30 October 1943, the necessity for an organization was expressed in the Moscow Declaration, agreed upon by China, the United Kingdom, the United States. This was followed by the Dumbarton Oaks Conference proposals of 9 October 1944, a prominent figure in the initiative for UNESCO was Rab Butler, the Minister of Education for the United Kingdom. At the ECO/CONF, the Constitution of UNESCO was introduced and signed by 37 countries, the Preparatory Commission operated between 16 November 1945, and 4 November 1946—the date when UNESCOs Constitution came into force with the deposit of the twentieth ratification by a member state. The first General Conference took place between 19 November to 10 December 1946, and elected Dr. Julian Huxley to Director-General and this change in governance distinguished UNESCO from its predecessor, the CICI, in how member states would work together in the organizations fields of competence. In 1956, the Republic of South Africa withdrew from UNESCO claiming that some of the organizations publications amounted to interference in the racial problems. South Africa rejoined the organization in 1994 under the leadership of Nelson Mandela, UNESCOs early work in the field of education included the pilot project on fundamental education in the Marbial Valley, Haiti, started in 1947. This project was followed by missions to other countries, including, for example. In 1948, UNESCO recommended that Member States should make free primary education compulsory, in 1990, the World Conference on Education for All, in Jomtien, Thailand, launched a global movement to provide basic education for all children, youths and adults. Ten years later, the 2000 World Education Forum held in Dakar, Senegal, UNESCOs early activities in culture included, for example, the Nubia Campaign, launched in 1960. The purpose of the campaign was to move the Great Temple of Abu Simbel to keep it from being swamped by the Nile after construction of the Aswan Dam, during the 20-year campaign,22 monuments and architectural complexes were relocated. This was the first and largest in a series of campaigns including Mohenjo-daro, Fes, Kathmandu, Borobudur, the organizations work on heritage led to the adoption, in 1972, of the Convention concerning the Protection of the World Cultural and Natural Heritage. The World Heritage Committee was established in 1976 and the first sites inscribed on the World Heritage List in 1978, since then important legal instruments on cultural heritage and diversity have been adopted by UNESCO member states in 2003 and 2005
UNESCO
–
UNESCO offices in
Brasília
UNESCO
–
UNESCO
UNESCO
–
UNESCO Institute for Water Education in
Delft
UNESCO
–
The Garden of Peace, UNESCO headquarters, Paris. Donated by the Government of Japan, this garden was designed by American-Japanese sculptor artist Isamu Noguchi in 1958 and installed by Japanese gardener Toemon Sano.
15.
Surveying
–
Surveying or land surveying is the technique, profession, and science of determining the terrestrial or three-dimensional position of points and the distances and angles between them. A land surveying professional is called a land surveyor, Surveyors work with elements of geometry, trigonometry, regression analysis, physics, engineering, metrology, programming languages and the law. Surveying has been an element in the development of the environment since the beginning of recorded history. The planning and execution of most forms of construction require it and it is also used in transport, communications, mapping, and the definition of legal boundaries for land ownership. It is an important tool for research in other scientific disciplines. Basic surveyance has occurred since humans built the first large structures, the prehistoric monument at Stonehenge was set out by prehistoric surveyors using peg and rope geometry. In ancient Egypt, a rope stretcher would use simple geometry to re-establish boundaries after the floods of the Nile River. The almost perfect squareness and north-south orientation of the Great Pyramid of Giza, built c.2700 BC, the Groma instrument originated in Mesopotamia. The mathematician Liu Hui described ways of measuring distant objects in his work Haidao Suanjing or The Sea Island Mathematical Manual, the Romans recognized land surveyors as a profession. They established the basic measurements under which the Roman Empire was divided, Roman surveyors were known as Gromatici. In medieval Europe, beating the bounds maintained the boundaries of a village or parish and this was the practice of gathering a group of residents and walking around the parish or village to establish a communal memory of the boundaries. Young boys were included to ensure the memory lasted as long as possible, in England, William the Conqueror commissioned the Domesday Book in 1086. It recorded the names of all the owners, the area of land they owned, the quality of the land. It did not include maps showing exact locations, abel Foullon described a plane table in 1551, but it is thought that the instrument was in use earlier as his description is of a developed instrument. Gunters chain was introduced in 1620 by English mathematician Edmund Gunter and it enabled plots of land to be accurately surveyed and plotted for legal and commercial purposes. Leonard Digges described a Theodolite that measured horizontal angles in his book A geometric practice named Pantometria, joshua Habermel created a theodolite with a compass and tripod in 1576. Johnathon Sission was the first to incorporate a telescope on a theodolite in 1725, in the 18th century, modern techniques and instruments for surveying began to be used. Jesse Ramsden introduced the first precision theodolite in 1787 and it was an instrument for measuring angles in the horizontal and vertical planes
Surveying
–
A surveyor at work with an infrared reflector used for distance measurement.
Surveying
–
Table of Surveying, 1728
Cyclopaedia
Surveying
–
A map of India showing the Great Trigonometrical Survey, produced in 1870
Surveying
–
A German engineer surveying during the
First World War, 1918
16.
William Gosse (explorer)
–
William Christie Gosse, was an Australian explorer, who was born in Hoddesdon, Hertfordshire, England and migrated to Australia with his father Dr. William Gosse in 1850. He was educated at J. L. Youngs Adelaide Educational Institution and he held various positions in the survey department, including Deputy Surveyor-General. He died of an attack on 12 August 1881, aged 38. Although Gosses exploration was not groundbreaking, he filled in details in the central map. He named the Musgrave Ranges and was able correctly to lay down the position of some of the discoveries of Ernest Giles, on 19 July 1873 he reached Uluru and gave it the name Ayers Rock. His second-in-charge, Edwin S. Berry was probably the first white man to climb The Rock, Gosse married Agnes Aggie Hay, a daughter of Alexander Hay and his first wife Agnes née Kelly on 22 December 1874. William and Aggie had three children, William Hay Gosse MC was killed in action in France and he married Muriel, née Davidson, who died in 1920. Their son George Gosse was awarded the George Cross in 1946, Sir James Hay Gosse married Joanna Lang, daughter of Tom Elder Barr Smith – they had a daughter and four sons, a brother-in-law, and also nephew, William Gosse Hay was an author. A sister-in-law, and also niece, Helen, and her mother, were lost at sea on the ill-fated SS Waratah, other descendants include former Australian Minister for Foreign Affairs, Alexander Downer. In 1931, the Hundred of Gosse, a division located on Kangaroo Island in South Australia was named in Gosses memory. In 1976 he was honoured on a stamp bearing his portrait issued by Australia Post. Gosses Bluff crater Gosse, South Australia
William Gosse (explorer)
–
William Gosse
17.
Henry Ayers
–
Sir Henry Ayers GCMG was the eighth Premier of South Australia, serving a record five times between 1863 and 1873. Historians note that his memorial is in the name of Ayers Rock. Ayers was born at Portsea, Portsmouth, Hampshire, England, the son of William Ayers, of the Portsmouth dockyard, educated at the Beneficial Societys School he entered a law office in 1832. He emigrated, as a carpenter, to South Australia in 1840 with his wife, until 1845 he worked as a law clerk, he was then appointed secretary of the Burra Burra mines. Henry Roach was chief Captain, responsible for operations, from 1847 to 1867. Within a year the mine employed over 1000 men. For nearly 50 years, Ayers was in control of mine, initially as the secretary. He made his wealth from the Burra Burra Copper Mines, which was known as the Monster Mine, on 9 March 1857 Ayers was elected to the first South Australian Legislative Council under responsible government, the youngest member elected. He was continuously a member for over 36 years, for many years the whole colony formed a single electorate for the council, on two occasions Ayers headed the poll. In March 1863 Ayers was selected as one of the three South Australian representatives at the conference on uniform tariffs and inland customs duties. He also represented the colony at several other conferences from 1864 to 1877, on 4 July 1863 Ayers became minister without portfolio in the first Dutton cabinet. This ministry resigned just 11 days later however, as council demanded that it should have a minister to represent the government. Ayers formed his first ministry as Premier and Chief Secretary on 15 July 1863, the house was much divided and it was almost impossible to get business done. Ayers reconstructed his ministry on 22 July 1864 but was defeated, the Blyth ministry which was then formed included Ayers as chief secretary, but did not survive a general election and resigned on 22 March 1865. In spite of dissolutions it was very difficult to get a workable house. There were 18 ministries tween July 1863 and July 1873, Ayers became the premier again from May 1867 to September 1868, October to November 1868,27 January 1872 to March 1872, and with an entirely new team of ministers, from March 1872 to July 1873. He held the position of secretary in the Colton ministry from June 1876 to October 1877. In 1881 Ayers was elected President of the South Australian Legislative Council and he died in Adelaide on 11 June 1897. His wife had died in 1881, and he was survived by three sons and a daughter and he was created a CMG in 1870, knighted a KCMG in 1872, and raised to GCMG in 1894
Henry Ayers
–
The Honourable Sir Henry Ayers
GCMG
18.
Dual naming
–
Dual naming is a policy for the naming of geographical landmarks, in which an official name is adopted that combines two previous names. Usually, the context is a conflict over which of the two names is most appropriate. In several countries, dual naming is used where a native people, in Australia, a dual naming policy is used to name landmarks that are of significance to the Indigenous Australians, but for which the most common name is European. For example, the landmark with the indigenous name Uluru and European name Ayers Rock is now officially named Uluru / Ayers Rock, similarly, many places in New Zealand have dual Maori and English names, such as Aoraki/Mount Cook. The practise of officially giving certain New Zealand places dual names began in the 1920s, the Derry stroke Londonderry spoken form of this has in turn engendered the citys nickname Stroke City. In Romania, the city of Cluj was renamed Cluj-Napoca for political reasons in the 1970s, another example of the phenomenon can be seed in the name of the capital of the Spanish Basque Country, Vitoria-Gasteiz. This combines the citys Spanish name of Vitoria and Basque name of Gasteiz, the official name of the bilingual Swiss town of Biel/Bienne is the combination of its German name and its French name. In Finland, many towns have two names, one in Finnish and one in Swedish, the two names are considered equally correct but are not used as a formal duality of names. A special problem occurs when the lies on the border between two countries, for example Mount Everest has several different locally-used names. List of dual names in New Zealand Names of places in Finland in Finnish
Dual naming
–
v
19.
Bush food
–
Examples of Australian native animal foods include kangaroo, emu and crocodile. In particular, kangaroo is quite common and can be found in Australian supermarkets, other animals, for example goanna and witchetty grubs, were eaten by Aboriginal Australians. Fish and shellfish are culinary features of the Australian coastal communities, examples of Australian native plant foods include the fruits quandong, kutjera, muntries, riberry, Davidsons plum, and finger lime. Native spices include lemon myrtle, mountain pepper, and aniseed myrtle, a popular leafy vegetable is warrigal greens. Nuts include bunya nut, and the most identifiable bush tucker plant harvested, knowledge of Aboriginal uses of fungi is meagre but beefsteak fungus and native bread, were certainly eaten. Aboriginal Australians have eaten native animal and plant foods for an estimated 60,000 years of habitation on the Australian continent. Various traditional methods of processing and cooking are used, toxic seeds, such as Cycas media and Moreton Bay chestnut, are processed to remove the toxins and render them safe to eat. Many foods are baked in the hot campfire coals, or baked for several hours in ground ovens. Paperbark, the bark of Melaleuca species, is used for wrapping food placed in ground ovens. Bush bread was made by using many types of seeds, nuts. Aboriginal traditional native food use has been affected by non-indigenous immigration since 1788. There, the introduction of foods to Aboriginals has resulted in an almost complete abandonment of native foods by Aboriginals. The recent recognition of the nutritional and gourmet value of foods by non-indigenous Australians is introducing native cuisine to many for the first time. Bush tucker provided a source of nutrition to the colonial settlers. However, bushfoods were often considered to be inferior by colonists unfamiliar with the new lands food ingredients, in the 19th century English botanist, J. D. Hooker, writing of Australian plants in Flora of Tasmania, remarked although eatable, are not fit to eat. In 1889, botanist Joseph Maiden reiterated this sentiment with the comment on native food plants nothing to boast of as eatables, the first monograph to be published on the flora of Australia reported the lack of edible plants on the first page, where it presented Billardiera scandens as. Almost the only wild eatable fruit of the country and this became the accepted view of Australian native food plants until the late 20th century. The only Australian native plant food developed and cropped on a scale is the macadamia nut
Bush food
–
Alice Springs Desert Park, Bush Tucker
Bush food
–
Billardiera scandens
Bush food
–
Great Morinda
Bush food
–
Desert Quandong
20.
Dreamtime
–
Dreamtime is a term devised by early anthropologists to refer to a religio-cultural worldview attributed to Australian Aboriginal beliefs. It was originally used by Francis Gillen, quickly adopted by his colleague Baldwin Spencer and thereafter popularised by A. P. Elkin and they were often distinct from gods as they did not control the material world and were not worshipped, but only revered. The term is based on a rendition of the indigenous word alcheringa, used by the Aranda people of Central Australia, william Stanner remarked, why the blackfellow thinks of dreaming as the nearest equivalent in English is a puzzle. It has been argued that the meaning is closer to eternal. By the 1980s, Dreamtime and the Dreaming had acquired their own currency in popular culture, the station-master, magistrate and amateur ethnographer Francis Gillen first used the terms in an ethnographical report in 1896. With Baldwin Spencer Gillen, he published in 1899 a major work, in that work, they spoke of the Alcheringa as the name applied to the far distant past with which the earliest traditions of the tribe deal. In the Arrernte tongue, the verb for to dream was altjirerama. The noun is the rare word altjirrinja, of which Spencer and Gillen gave a corrupted transcription. The native, they concluded, knows nothing of dreamtime as a designation of a period of their history. Related entities are known as Mura-mura by the Dieri and as Tjukurpa in Pitjantjatjara and this is because in Dreamtime an individuals entire ancestry exists as one, culminating in the idea that all worldly knowledge is accumulated through ones ancestors. Many Indigenous Australians also refer to the Creation time as The Dreaming, the Dreamtime laid down the patterns of life for the Aboriginal people. Creation is believed to be the work of culture heroes who traveled across a land, creating sacred sites. In this way, songlines were established, some of which could travel right across Australia, the dreaming and travelling trails of the Spirit Beings are the songlines. The signs of the Spirit Beings may be of spiritual essence, physical remains such as petrosomatoglyphs of body impressions or footprints, Dreaming existed before the life of the individual begins, and continues to exist when the life of the individual ends. Both before and after life, it is believed that this exists in the Dreaming and is only initiated into life by being born through a mother. The spirit of the child is culturally understood to enter the fetus during the fifth month of pregnancy. When the mother felt the move in the womb for the first time. Upon birth, the child is considered to be a special custodian of that part of their country and is taught the stories and songlines of that place, as Wolf states, A black fella may regard his totem or the place from which his spirit came as his Dreaming
Dreamtime
–
Stencil art at
Carnarvon Gorge, supposedly showing "unique clan markers and dreamtime stories symbolising attempts to catch the deceased's spirit". [
citation needed]
Dreamtime
–
Waugals (yellow triangles with a black snake in the centre) are the official
Bibbulmun Track trailmarkers between
Kalamunda and
Albany in Western Australia. The Noongar believe that the Waugal, or Wagyl, created the Swan River and is represented by the Darling scarp.
Dreamtime
–
Ku-ring-gai Chase-petroglyph, via Waratah Track, depicting
Baiame, the Creator God and Sky Father in the dreaming of several Aboriginal language groups.
21.
Color constancy
–
A green apple for instance looks green to us at midday, when the main illumination is white sunlight, and also at sunset, when the main illumination is red. Color vision is a process by which organisms and machines are able to distinguish based on the different wavelengths of light reflected, transmitted. Color constancy is a process allows the brain to recognize a familiar object as being a consistent color regardless of the amount or wavelengths of light reflecting from it at a given moment. These specialized cells are called double-opponent cells because they compute both color opponency and spatial opponency, double-opponent cells were first described by Nigel Daw in the goldfish retina. Color constancy works only if the incident illumination contains a range of wavelengths, the different cone cells of the eye register different but overlapping ranges of wavelengths of the light reflected by every object in the scene. From this information, the system attempts to determine the approximate composition of the illuminating light. This illumination is then discounted in order to obtain the true color or reflectance. This reflectance then largely determines the perceived color, the effect was described in 1971 by Edwin H. Land, who formulated retinex theory to explain it. The word retinex is a formed from retina and cortex. The effect can be demonstrated as follows. A display called a Mondrian consisting of colored patches is shown to a person. The display is illuminated by three white lights, one projected through a red filter, one projected through a green filter, the person is asked to adjust the intensity of the lights so that a particular patch in the display appears white. The experimenter then measures the intensities of red, green, then the experimenter asks the person to identify the color of a neighboring patch, which, for example, appears green. Then the experimenter adjusts the lights so that the intensities of red, blue, the person shows color constancy in that the green patch continues to appear green, the white patch continues to appear white, and all the remaining patches continue to have their original colors. Color constancy is a feature of computer vision, and many algorithms have been developed for this purpose. These algorithms receive as input the red/green/blue values of each pixel of the image, one such algorithm operates as follows, the maximal red value rmax of all pixels is determined, and also the maximal green value gmax and the maximal blue value bmax. For each pixel with values its reflectance is estimated as, the original retinex algorithm proposed by Land and McCann uses a localized version of this principle. Although retinex models are widely used in computer vision, actual human color perception has been shown to be more complex
Color constancy
–
Color constancy: The colors of a
hot air balloon are recognized as being the same in sun and shade
Color constancy
–
Automatically making assumptions about
reflectance and the type and source of light
Color constancy
–
Achieving luminance constancy by retinex filtering for image analysis
Color constancy
–
The second card from the left seems to be a stronger shade of pink in the top picture. In fact they are the same color, but the brain changes its assumption about color due to the color cast of the surrounding photo.
22.
Sunset
–
Sunset or sundown, is the daily disappearance of the Sun below the horizon as a result of Earths rotation. The Sun will set exactly due west at the equator on the spring and fall equinoxes, the time of sunset is defined in astronomy as the moment when the trailing edge of the Suns disk disappears below the horizon. Dusk is at the end of astronomical twilight, and is the darkest moment of twilight just before night. Sunset creates unique atmospheric conditions such as the intense orange and red colors of the Sun. The time of sunset varies throughout the year, and is determined by the position on Earth, specified by longitude and latitude. During winter and spring, the days get longer and sunsets occur later every day until the day of the latest sunset, in the Northern Hemisphere, the latest sunset occurs late in June or in early July, but not on the summer solstice of June 21. This date depends on the viewers latitude, likewise, the earliest sunset does not occur on the winter solstice, but rather about two weeks earlier, again depending on the viewers latitude. In the Northern Hemisphere, it occurs in early December or late November, for a few weeks surrounding both solstices, both sunrise and sunset get slightly later each day. Even on the equator, sunrise and sunset shift several minutes back and forth through the year and these effects are plotted by an analemma. Sunsets occur almost exactly due west on the equinoxes for all viewers on Earth, exact calculations of the azimuths of sunset on other dates are complex, but they can be estimated with reasonable accuracy by using the analemma. As sunrise and sunset are calculated from the leading and trailing edges of the Sun, respectively, and not the center, the duration of a daytime is slightly longer than nighttime. Further, because the light from the Sun is refracted as it passes through the Earths atmosphere, refraction also affects the apparent shape of the Sun when it is very close to the horizon. It makes things appear higher in the sky than they really are, light from the bottom edge of the Suns disk is refracted more than light from the top, since refraction increases as the angle of elevation decreases. This raises the apparent position of the edge more than the top. Its width is unaltered, so the disk appears wider than it is high, the Sun also appears larger on the horizon, an optical illusion, similar to the moon illusion. Because the shorter wavelength components, such as blue and green, scatter more strongly, the remaining reddened sunlight can then be scattered by cloud droplets and other relatively large particles to light up the horizon red and orange. The removal of the wavelengths of light is due to Rayleigh scattering by air molecules and particles much smaller than the wavelength of visible light. The scattering by cloud droplets and other particles with diameters comparable to or larger than the sunlights wavelengths is due to Mie scattering and is not strongly wavelength-dependent
Sunset
–
The
Sun, about a minute before sunset.
Portugal, October 2007.
Sunset
–
Click this image to see the full cycle of a Sunset on the High Plains of the
Mojave Desert
Sunset
–
Evening
Twilight in
Joshua Tree, California, USA displaying the separation of orange colors in the direction from the Sun below the
Horizon to the observer; and the blue components scattered from the surrounding sky.
Sunset
–
Illuminated downdraft wind shear
clouds in the eastern sky near
Dusk, mimic
Aurora Borealis in the
Mojave Desert
23.
Inselberg
–
An inselberg or monadnock is an isolated rock hill, knob, ridge, or small mountain that rises abruptly from a gently sloping or virtually level surrounding plain. In southern and south-central Africa, a formation of granite is known as a koppie. If the inselberg is dome-shaped and formed from granite or gneiss, it can also be called a bornhardt, plains containing various inselbergs, inselberg plains, occur in various parts of the world including the interior of Angola, Namibia, Tanzania, Northern Finland and Swedish Lapland. An example of an inselberg is Uluru in Australia, the word inselberg is German for island mountain, the name was coined by geologist Wilhelm Bornhardt in 1900 to describe the abundance of such features found in southern Africa. At that time, the term applied only to landscape features. However, the term inselberg has since used to describe a broader geography and range of rock features. As recently as 1972, the term has been defined as steep-sided isolated hills rising abruptly above gently sloping ground. Thus, the terms monadnock and inselberg may not perfectly match, Monadnock is an originally Native American term for an isolated hill or a lone mountain that stands above the surrounding area, typically by surviving erosion. Geologists took the name from Mount Monadnock in southwestern New Hampshire and it is thought to derive from the Abenaki language, from either menonadenak or menadena. In this context, monadnock is used to describe a mountain that rises from an area of relatively flat and/or lower terrain. For instance, Mount Monadnock rises 2,000 feet above its terrain and stands, at 3,165 feet. Volcanic or other processes may give rise to a body of rock resistant to erosion, inside a body of rock such as limestone. When the less resistant rock is eroded away to form a plain, the strength of the uneroded rock is often attributed to the tightness of its jointing. The presence of a monadnock or inselberg typically indicates the existence of a plateau or highland. This is especially the case for inselbergs composed of sedimentary rock, however once exposed, the inselbergs are destroyed by marginal collapse of joint blocks and exfoliation sheets. This process leaves behind tors perched at their summits and, over time, inselbergs can be reshaped by ice sheets much the same way as roche moutonnées. In northern Sweden this kind of inselbergs have been referred as flyggbergs, the kopjes of Eastern Africa tend to be a refuge for life in the Serengeti of Tanzania and Kenya. Where the soil is too thin or hard to support life in large areas
Inselberg
–
Inselberg in the state of
Bahia, northwestern
Brazil.
Inselberg
Inselberg
–
Mount Monadnock in New Hampshire, United States
Inselberg
–
Pietra di Bismantova in the
Apennines,
Italy
24.
Joint (geology)
–
A joint is a break of natural origin in the continuity of either a layer or body of rock that lacks any visible or measurable movement parallel to the surface of the fracture. Although they can occur singly, they most frequently occur as joint sets, a joint set is a family of parallel, evenly spaced joints that can be identified through mapping and analysis of the orientations, spacing, and physical properties. A joint system consists of two or more intersecting joint sets, the distinction between joints and faults hinges on the terms visible or measurable which depends on the scale of observation. Faults differ from joints in that they exhibit visible or measurable lateral movement between the surfaces of the fracture. Joints are among the most universal geologic structures as they are found in most every exposure of rock and they vary greatly in appearance, dimensions, and arrangement, and occur in quite different tectonic environments. Often, the origin of the stresses that created certain joints and associated joint sets can be quite ambiguous, unclear. The most prominent joints occur in the most well-consolidated, lithified, and highly competent rocks, such as sandstone, limestone, quartzite, Joints may be open fractures or filled by various materials. Joints, which are infilled by precipitated minerals are called veins, Joints result from brittle fracture of a rock body or layer as the result of tensile stresses. These tensile stresses either were induced or imposed from outside, e. g, when tensional stresses stretch a body or layer of rock such that its tensile strength is exceeded, it breaks. When this happens the rock fractures in a parallel to the maximum principal stress. This leads to the development of a single sub-parallel joint set, continued deformation may lead to development of one or more additional joint sets. The presence of the first set strongly affects the orientation in the rock layer, often causing subsequent sets to form at a high angle, often 90°. Joints are classified either by the responsible for their formation or their geometry. The geometry of joints refers to the orientation of joints as either plotted on stereonets, in terms of geometry, three major types of joints, nonsystematic joints, systematic joints, and columnar jointing are recognized. Nonsystematic joints are joints that are so irregular in form, spacing, as a result, they occur as families of joints that form recognizable joint sets. Based upon the angle at which joint sets of systematic joints intersect to form a joint system, systematic joints can be subdivided into conjugate, the angles at which joint sets within a joint system commonly intersect is called by structural geologists as the dihedral angles. When the dihedral angles are nearly 90° within a joint system, when the dihedral angles are from 30 to 60° within a joint system, the joint sets are known as conjugate joint sets. Within regions that have experienced tectonic deformation, systematic joints are typically associated with either layered or bedded strata that has folded into anticlines and synclines
Joint (geology)
–
Sub-horizontal joints in the sedimentary rocks of the foreground and a more varied set of joints in the granitic rocks in the background. Image from the
Kazakh Uplands in
Balkhash District,
Kazakhstan.
Joint (geology)
–
Orthogonal joint sets on a
bedding plane in
flagstones,
Caithness,
Scotland
Joint (geology)
–
A rock in
Abisko fractured along existing joints possibly by mechanical
frost weathering
Joint (geology)
–
Columnar jointed basalt in
Turkey
25.
Bed (geology)
–
In geology a bed is the smallest division of a geologic formation or stratigraphic rock series marked by well-defined divisional planes separating it from layers above and below. A bed is the smallest lithostratigraphic unit, usually ranging in thickness from a centimetre to several metres and distinguishable from beds above, beds can be differentiated in various ways, including rock or mineral type and particle size. The term is applied to sedimentary strata, but may also be used for volcanic flows or ash layers. In a quarry, a bedding is a used for a structure occurring in granite. Three kinds of beds are, parallel beds, cross beds, geological unit Lamination Stratigraphy Stratum Lamina, Laminaset, Bed and Bedset
Bed (geology)
–
Sedimentary bedding (Turkey)
26.
Scree
–
Scree is a collection of broken rock fragments at the base of crags, mountain cliffs, volcanoes or valley shoulders that has accumulated through periodic rockfall from adjacent cliff faces. Landforms associated with these materials are called talus deposits. Talus deposits typically have a concave form, while the maximum inclination corresponds to the angle of repose of the mean debris size. The term scree comes from the Old Norse term for landslide, skriða, formation of scree or talus deposits the results of physical and chemical weathering and erosion acting on a rock face. During the day, water can flow into joints and discontinuities in the rock wall, if the temperature drops enough, for example in the evening, this water may freeze. Since water expands by 9% when it freezes, it can generate forces that either create new cracks or wedge blocks into an unstable position. Special boundary conditions may be required for this to happen, the efficiency of freeze/thaw processes in scree production is debated by scientists. Many researchers believe that ice formation in large open crack systems cannot generate high pressures, many argue that frost heaving, like that known to act in soil in permafrost areas, may play an important role in cliff degradation in cold places. For example, Lech dl Dragon, in the Sella Group of the Dolomites, derives from the waters of a glacier. The melting process of the glacier is slowed by the protective layer of scree. Eventually a rock slope may be covered by its own scree. The slope is then said to be mantled with debris, fellfield Lava stringer Mass wasting Weathering
Scree
–
Talus at the bottom of
Mount Yamnuska,
Alberta,
Canada.
Scree
–
Climber on talus slope on the west flank of
Cross Fell,
England.
Scree
–
Talus cones on north shore of
Isfjord,
Svalbard,
Norway.
Scree
–
The lake
Lech dl Dragon in the
Dolomites,
Italy.
27.
Stratum
–
In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers. The stratum is the unit in a stratigraphic column and forms the basis of the study of stratigraphy. Each layer is one of a number of parallel layers that lie one upon another. They may extend over hundreds of thousands of kilometers of the Earths surface. Strata are typically seen as bands of different colored or differently structured material exposed in cliffs, road cuts, quarries, individual bands may vary in thickness from a few millimeters to a kilometer or more. Each band represents a mode of deposition, river silt, beach sand, coal swamp, sand dune, lava bed. Geologists study rock strata and categorize them by the material of beds, each distinct layer is typically assigned to the name of sheet, usually based on a town, river, mountain, or region where the formation is exposed and available for study. For example, the Burgess Shale is an exposure of dark, occasionally fossiliferous. Slight distinctions in material in a formation may be described as members, formations are collected into groups while groups may be collected into supergroups. Archaeological horizon Geologic formation Geologic map Geologic unit Law of superposition Bed GeoWhen Database
Stratum
–
Strata in
Salta (
Argentina).
Stratum
–
Goldenville strata in quarry in
Bedford,
Canada. These are
Middle Cambrian marine sediments. This formation covers over half of
Nova Scotia and is recorded as being 29,000 feet thick in some areas.
Stratum
Stratum
28.
Sedimentary rock
–
Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of that material at the Earths surface and within bodies of water. Sedimentation is the name for processes that cause mineral and/or organic particles to settle in place. The particles that form a rock by accumulating are called sediment. Sedimentation may also occur as minerals precipitate from solution or shells of aquatic creatures settle out of suspension. The sedimentary rock cover of the continents of the Earths crust is extensive, sedimentary rocks are only a thin veneer over a crust consisting mainly of igneous and metamorphic rocks. Sedimentary rocks are deposited in layers as strata, forming a structure called bedding, sedimentary rocks are also important sources of natural resources like coal, fossil fuels, drinking water or ores. The study of the sequence of rock strata is the main source for an understanding of the Earths history, including palaeogeography, paleoclimatology. The scientific discipline that studies the properties and origin of rocks is called sedimentology. Sedimentology is part of both geology and physical geography and overlaps partly with other disciplines in the Earth sciences, such as pedology, geomorphology, geochemistry, sedimentary rocks have also been found on Mars. Clastic sedimentary rocks are composed of rock fragments that were cemented by silicate minerals. Clastic rocks are composed largely of quartz, feldspar, rock fragments, clay minerals, and mica, any type of mineral may be present, clastic sedimentary rocks, are subdivided according to the dominant particle size. Most geologists use the Udden-Wentworth grain size scale and divide unconsolidated sediment into three fractions, gravel, sand, and mud and this tripartite subdivision is mirrored by the broad categories of rudites, arenites, and lutites, respectively, in older literature. The subdivision of these three categories is based on differences in clast shape, conglomerates and breccias), composition. Conglomerates are dominantly composed of rounded gravel, while breccias are composed of dominantly angular gravel, composition of framework grains The relative abundance of sand-sized framework grains determines the first word in a sandstone name. Naming depends on the dominance of the three most abundant components quartz, feldspar, or the lithic fragments that originated from other rocks, all other minerals are considered accessories and not used in the naming of the rock, regardless of abundance. Clean sandstones with open space are called arenites. Muddy sandstones with abundant muddy matrix are called wackes, six sandstone names are possible using the descriptors for grain composition and the amount of matrix. Mudrocks are sedimentary rocks composed of at least 50% silt- and clay-sized particles and these relatively fine-grained particles are commonly transported by turbulent flow in water or air, and deposited as the flow calms and the particles settle out of suspension
Sedimentary rock
–
Middle
Triassic marginal marine sequence of siltstones (reddish layers at the cliff base) and limestones (brown rocks above),
Virgin Formation, southwestern
Utah, USA
Sedimentary rock
–
Sedimentary rocks on Mars, investigated by NASA's
Curiosity Mars rover
Sedimentary rock
–
Steeply dipping sedimentary rock strata along the
Chalous Road in northern
Iran
Sedimentary rock
–
Claystone deposited in
Glacial Lake Missoula,
Montana,
United States. Note the very fine and flat bedding, common for distal
lacustrine deposition.
29.
Amadeus Basin
–
The Amadeus Basin is a large intracratonic sedimentary basin in central Australia, lying mostly within the southern Northern Territory, but extending into the state of Western Australia. The Amadeus Basin is named after Lake Amadeus which lies within the basin, local deposition of up to 14 km of marine and non-marine sedimentary rocks took place from the Neoproterozoic to the late Paleozoic. Along with other sedimentary basins of similar age, the Amadeus Basin is believed to have once been part of the hypothetical Centralian Superbasin. The basin was deformed during the Petermann Orogeny, and more extensively during the Paleozoic Alice Springs Orogeny. The basin has been above water for the past 50 million years, as the modern coast of South Australia, the Amadeus Basin contains the producing Mereenie Oilfield near Kings Canyon and Palm Valley Gasfield near Hermannsburg, which supply most of the energy resources to the Northern Territory. Most of the gas flows along a pipeline to Darwin, while the oil is pumped to Alice Springs, Alice Springs Orogeny Georgina Basin Ngalia Basin Officer Basin Petermann Orogeny Wells AT, Forman DJ, Ranford LC, Cook PJ Geology of the Amadeus Basin, Central Australia. Bureau of Mineral Resources, Australia, Bulletin 100, lindsay JF, Korsch RJ The evolution of the Amadeus Basin, central Australia. In Korsch RJ, & Kennard JM. Geological and geophysical studies in the Amadeus Basin, bureau of Mineral Resources, Australia, Bulletin 236, 7-32. Shaw RD The tectonic development of the Amadeus Basin, central Australia, in Korsch RJ, & Kennard JM. Geological and geophysical studies in the Amadeus Basin, central Australia. Bureau of Mineral Resources, Australia, Bulletin 236, 429-462, Amadeus Basin at Geoscience Australia Amadeus Basin at Northern Territory Geological Survey
Amadeus Basin
–
from space (November 1994)
30.
Feldspar
–
Feldspars are a group of rock-forming tectosilicate minerals that make up about 40% of the Earths continental crust. Feldspars crystallize from magma as veins in both intrusive and extrusive rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of plagioclase feldspar is known as anorthosite. Feldspars are also found in types of sedimentary rocks. The name feldspar derives from the German Feldspat, a compound of the words Feld, field, and Spat, the change from Spat to -spar was influenced by the English word spar, a synonym for mineral. Feldspathic refers to materials that contain feldspar, the alternate spelling, felspar, has largely fallen out of use. This group of minerals consists of tectosilicates, solid solutions between albite and anorthite are called plagioclase, or more properly plagioclase feldspar. Only limited solid solution occurs between K-feldspar and anorthite, and in the two solid solutions, immiscibility occurs at temperatures common in the crust of the earth. Albite is considered both a plagioclase and alkali feldspar, the alkali feldspars are as follows, orthoclase —KAlSi3O8 sanidine —AlSi3O8 microcline —KAlSi3O8 anorthoclase —AlSi3O8 Sanidine is stable at the highest temperatures, and microcline at the lowest. Perthite is a texture in alkali feldspar, due to exsolution of contrasting alkali feldspar compositions during cooling of an intermediate composition. The perthitic textures in the alkali feldspars of many granites can be seen with the naked eye, microperthitic textures in crystals are visible using a light microscope, whereas cryptoperthitic textures can be seen only with an electron microscope. Barium feldspars are also considered alkali feldspars, barium feldspars form as the result of the substitution of barium for potassium in the mineral structure. The barium feldspars are monoclinic and include the following, celsian—BaAl2Si2O8 hyalophane—4O8 The plagioclase feldspars are triclinic, the immiscibility gaps in the plagioclase solid solutions are complex compared to the gap in the alkali feldspars. The play of colours visible in some feldspar of labradorite composition is due to very fine-grained exsolution lamellae, chemical weathering of feldspars results in the formation of clay minerals. About 20 million tonnes of feldspar were produced in 2010, mostly by three countries, Italy, Turkey, and China, Feldspar is a common raw material used in glassmaking, ceramics, and to some extent as a filler and extender in paint, plastics, and rubber. In glassmaking, alumina from feldspar improves product hardness, durability, in ceramics, the alkalis in feldspar act as a flux, lowering the melting temperature of a mixture. Fluxes melt at a stage in the firing process, forming a glassy matrix that bonds the other components of the system together. In the US, about 66% of feldspar is consumed in glassmaking, including glass containers, ceramics and other uses, such as fillers, accounted for the remainder
Feldspar
–
Feldspar crystal (18×21×8.5 cm) from
Jequitinhonha valley,
Minas Gerais, Southeastern Brazil.
Feldspar
–
Compositional phase diagram of the different minerals that constitute the feldspar solid solution.
Feldspar
–
Lunar ferrous
anorthosite #60025 (
plagioclase feldspar). Collected by
Apollo 16 from the
Lunar Highlands near
Descartes Crater. This sample is currently on display at the
National Museum of Natural History in
Washington, D.C.
Feldspar
–
Labradorite.
31.
Conglomerate (geology)
–
Conglomerates form by the consolidation and lithification of gravel. The size and composition of the fraction of a conglomerate may or may not vary in composition, sorting. In some conglomerates, the gravel-size class consist almost entirely of what were clay clasts at the time of deposition, conglomerates can be found in sedimentary rock sequences of all ages but probably make up less than 1 percent by weight of all sedimentary rocks. A sedimentary rock composed largely of gravel is first named according to the roundness of the gravel, if the gravel clasts that comprise it is largely well-rounded to subrounded, it is a conglomerate. If the gravel clasts that comprise it are largely angular, it is a breccia, such breccias can be called sedimentary breccias to differentiate them from other types of breccia, e. g. volcanic and fault breccias. Sedimentary rocks that contain a mixture of rounded and angular gravel clasts are sometimes called breccio-conglomerate, conglomerates are rarely composed entirely of gravel-size clasts. Typically, the space between the gravel-size clasts is filled by a mixture composed of varying amounts of silt, sand, paraconglomerates are also often unstratified and can contain more matrix than gravel clasts. If the gravel clasts of a conglomerate are in contact with each other, unlike paraconglomerates, orthoconglomerates are typically cross-bedded and often well-cemented and lithified by either calcite, hematite, quartz, or clay. The differences between paraconglomerates and orthoconglomerates reflect differences in how they are deposited, paraconglomerates are commonly either glacial tills or debris flow deposits. Orthoconglomerates are typically associated with aqueous currents, conglomerates are also classified according to the composition of their clasts. A conglomerate or any clastic sedimentary rock that consists of a rock or mineral is known as either a monomict, monomictic, oligomict. If the conglomerate consists of two or more different types of rocks, minerals, or combination of both, it is known as either a polymict or polymictic conglomerate. If a polymictic conglomerate contains an assortment of the clasts of metastable and unstable rocks and minerals, two recognized types of type of intraformational conglomerates are shale-pebble and flat-pebble conglomerates. Finally, conglomerates are often differentiated and named according to the dominant clast size comprising them, conglomerates are deposited in a variety of sedimentary environments. In turbidites, the part of a bed is typically coarse-grained. In this setting, conglomerates are normally very well sorted, well-rounded, conglomerates are normally present at the base of sequences laid down during marine transgressions above an unconformity, and are known as basal conglomerates. They represent the position of the shoreline at a time and are diachronous. Conglomerates deposited in environments are typically well rounded and well sorted
Conglomerate (geology)
–
Boulder of conglomerate with cobble-sized clasts. Rock hammer for scale.
Conglomerate (geology)
–
Carmelo Formation (Conglomerate) at
Point Lobos
Conglomerate (geology)
–
A conglomerate at the base of the
Cambrian in the Black Hills, South Dakota.
Conglomerate (geology)
–
Section of polymict conglomerate from offshore rock
core,
Alaska, approximate depth 10,000 ft.
32.
Quartz
–
Quartz is the second most abundant mineral in Earths continental crust, behind feldspar. There are many different varieties of quartz, several of which are semi-precious gemstones, since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. The word quartz is derived from the German word Quarz and its Middle High German ancestor twarc, the Ancient Greeks referred to quartz as κρύσταλλος derived from the Ancient Greek κρύος meaning icy cold, because some philosophers apparently believed the mineral to be a form of supercooled ice. Today, the rock crystal is sometimes used as an alternative name for the purest form of quartz. Quartz belongs to the crystal system. The ideal crystal shape is a six-sided prism terminating with six-sided pyramids at each end, well-formed crystals typically form in a bed that has unconstrained growth into a void, usually the crystals are attached at the other end to a matrix and only one termination pyramid is present. However, doubly terminated crystals do occur where they develop freely without attachment, a quartz geode is such a situation where the void is approximately spherical in shape, lined with a bed of crystals pointing inward. α-quartz crystallizes in the crystal system, space group P3121 and P3221 respectively. β-quartz belongs to the system, space group P6222 and P6422. These space groups are truly chiral, both α-quartz and β-quartz are examples of chiral crystal structures composed of achiral building blocks. The transformation between α- and β-quartz only involves a comparatively minor rotation of the tetrahedra with respect to one another, although many of the varietal names historically arose from the color of the mineral, current scientific naming schemes refer primarily to the microstructure of the mineral. Color is an identifier for the cryptocrystalline minerals, although it is a primary identifier for the macrocrystalline varieties. Pure quartz, traditionally called rock crystal or clear quartz, is colorless and transparent or translucent, common colored varieties include citrine, rose quartz, amethyst, smoky quartz, milky quartz, and others. The most important distinction between types of quartz is that of macrocrystalline and the microcrystalline or cryptocrystalline varieties, the cryptocrystalline varieties are either translucent or mostly opaque, while the transparent varieties tend to be macrocrystalline. Chalcedony is a form of silica consisting of fine intergrowths of both quartz, and its monoclinic polymorph moganite. Other opaque gemstone varieties of quartz, or mixed rocks including quartz, often including contrasting bands or patterns of color, are agate, carnelian or sard, onyx, heliotrope, amethyst is a form of quartz that ranges from a bright to dark or dull purple color. The worlds largest deposits of amethysts can be found in Brazil, Mexico, Uruguay, Russia, France, Namibia, sometimes amethyst and citrine are found growing in the same crystal. It is then referred to as ametrine, an amethyst is formed when there is iron in the area where it was formed
Quartz
–
Quartz
crystal cluster from
Tibet
Quartz
–
Clear rock crystals on a white base
Quartz
–
Amethyst crystals on matrix
Quartz
–
Citrine from Brazil
33.
Plagioclase
–
Plagioclase is a series of tectosilicate minerals within the feldspar group. Rather than referring to a mineral with a specific chemical composition, plagioclase is a continuous solid solution series. This was first shown by the German mineralogist Johann Friedrich Christian Hessel in 1826, the series ranges from albite to anorthite endmembers, where sodium and calcium atoms can substitute for each other in the minerals crystal lattice structure. Plagioclase in hand samples is often identified by its polysynthetic crystal twinning or record-groove effect, plagioclase is a major constituent mineral in the Earths crust, and is consequently an important diagnostic tool in petrology for identifying the composition, origin and evolution of igneous rocks. Plagioclase is also a constituent of rock in the highlands of the Earths moon. Analysis of thermal emission spectra from the surface of Mars suggests that plagioclase is the most abundant mineral in the crust of Mars, the extinction angle is an optical characteristic and varies with the albite fraction. There are several named plagioclase feldspars that fall between albite and anorthite in the series, the following table shows their compositions in terms of constituent anorthite and albite percentages. Anorthite was named by Gustav Rose in 1823 from the Ancient Greek meaning oblique, anorthite is a comparatively rare mineral but occurs in the basic plutonic rocks of some orogenic calc-alkaline suites. Albite is named from the Latin albus, in reference to its pure white color. It is a common and important rock-making mineral associated with the more acid rock types and in pegmatite dikes, often with rarer minerals like tourmaline. The intermediate members of the group are very similar to each other. Bytownite, named after the name for Ottawa, Canada, is a rare mineral occasionally found in more basic rocks. Labradorite is the characteristic feldspar of the basic rock types such as diorite, gabbro, andesite. Labradorite frequently shows an iridescent display of colors due to light refracting within the lamellae of the crystal and it is named after Labrador, where it is a constituent of the intrusive igneous rock anorthosite which is composed almost entirely of plagioclase. A variety of known as spectrolite is found in Finland. Andesine is a mineral of rocks such as diorite which contain a moderate amount of silica. Oligoclase is common in granite, syenite, diorite, and gneiss and it is a frequent associate of orthoclase. The name oligoclase is derived from the Greek for little and fracture, sunstone is mainly oligoclase with flakes of hematite
Plagioclase
–
A
photomicrograph of a plagioclase
crystal under cross
polarized light. The plagioclase crystal shows a distinct banding effect called
polysynthetic twinning.
Plagioclase
–
Plagioclase displaying
cleavage. (unknown scale)
Plagioclase
–
In
volcanic rocks,
fine-grained plagioclase can display a 'microlitic' texture of many small
crystals.
Plagioclase
–
Anorthite
34.
Roundness (geology)
–
Roundness is the degree of smoothing due to abrasion of sedimentary particles. It is expressed as the ratio of the radius of curvature of the edges or corners to the radius of curvature of the maximum inscribed sphere. Rounding, roundness or angularity are terms used to describe the shape of the corners on a particle of sediment, such a particle may be a grain of sand, a pebble, cobble or boulder. Rounding of sediment particles can indicate the distance and time involved in the transportation of the sediment from the area to where it is deposited. Speed of rounding will depend on composition, hardness and mineral cleavage, for example, a soft claystone pebble will obviously round much faster, and over a shorter distance of transport, than a more resistant quartz pebble. The rate of rounding is also affected by the grain size, angularity and roundness are but two parameters of the complexity of a clasts generalised form. A defining expression is given by, F=f where f denotes a relationship between these terms and where Sh denotes the shape, Sp the sphericity and T the micro-scale surface texture. An example of practical use has been applied to the roundness of the grains in the Gulf of Mexico in order to observe the distance from the source rocks. Roundness is an important indicator of the affiliation of a clastic rock. The degree of roundness points to the range and mode of transport of clastic material, alluvial debris in major rivers tend to exhibit a high degree of roundness. Alluvium from small rivers is less rounded, deposits of ephemeral streams exhibit little rounding with angular clasts. Pebble dikes are dikelike bodies found in environments which contain variably rounded fragments. The clasts originate in deeper formations and have brought up by diatreme or intrusive breccias. The fragments have been rounded due to either milling action or corrosion by hydrothermal fluids, the ore deposits of Tintic mining district, Utah, Ouray, Colorado, Silver Bell, and Bisbee, Arizona and the Kiruna iron deposit in Sweden contain these pebble dikes. Sorting Sphericity Tumble finishing Mountain Encyclopedia, kulik, NA, Postnov AV Geology, petrography and mineralogy in archaeological research. - Methods of Earth and Man in archaeological research, Comprehensive Training Manual, - Novosibirsk, Novosibirsk State University, Institute of Archaeology and Ethnography SB RAS,2010
Roundness (geology)
–
Well-rounded
cobble from the beach on
Teletskoe Lake,
Altai Republic
Roundness (geology)
–
Rounded pebbles in a streambed
35.
Sorting (sediment)
–
Sorting describes the distribution of grain size of sediments, either in unconsolidated deposits or in sedimentary rocks. This should not be confused with crystallite size, which refers to the size of a crystal in a solid. Crystallite is the block of a grain. Very poorly sorted indicates that the sediment sizes are mixed, whereas well sorted indicates that the sediment sizes are similar, in the field, sedimentologists use graphical charts to accurately describe the sorting of a sediment using one of these words. The degree of sorting may also indicate the energy, rate, and/or duration of deposition, sorting of sediments can also be affected by reworking of the material after deposition, for instance, by winnowing. Well sorted rocks are generally porous, while poorly sorted rocks have low porosity, grain size Graded bedding Rounding Porosity Soil texture Sediment transport
Sorting (sediment)
–
Sediment consisting of well sorted grains (left) compared with poorly sorted grains (right).
36.
Grain size
–
Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials and this is different from the crystallite size, which refers to the size of a single crystal inside a particle or grain. A single grain can be composed of several crystals, granular material can range from very small colloidal particles, through clay, silt, sand, gravel, and cobbles, to boulders. Size ranges define limits of classes that are given names in the Wentworth scale used in the United States, the Krumbein phi scale, a modification of the Wentworth scale created by W. C. This equation can be rearranged to find diameter using φ, D = D0 ×2 − ϕ In some schemes, ISO 14688-1 is applicable to natural soils in situ, similar man-made materials in situ and soils redeposited by people. An accumulation of sediment can also be characterized by the size distribution. A sediment deposit can undergo sorting when a particle size range is removed by an agency such as a river or the wind, a Scale of Grade and Class Terms for Clastic Sediments
Grain size
–
Wentworth grain size chart from United States Geological Survey Open-File Report 2006-1195
Grain size
–
Beach cobbles (gravel) at Nash Point, South Wales.
Grain size
37.
Basalt
–
Basalt is a common extrusive igneous rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon. Flood basalt describes the formation in a series of basalt flows. By definition, basalt is an igneous rock with generally 45-55% silica and less than 10% feldspathoid by volume. Basalt commonly features a very fine-grained or glassy matrix interspersed with visible mineral grains, the average density is 3.0 gm/cm3. Basalt is defined by its content and texture, and physical descriptions without mineralogical context may be unreliable in some circumstances. Basalt is usually grey to black in colour, but rapidly weathers to brown or rust-red due to oxidation of its mafic minerals into hematite, although usually characterized as dark, basaltic rocks exhibit a wide range of shading due to regional geochemical processes. Due to weathering or high concentrations of plagioclase, some basalts can be quite light-coloured and these phenocrysts usually are of olivine or a calcium-rich plagioclase, which have the highest melting temperatures of the typical minerals that can crystallize from the melt. Basalt with a texture is called vesicular basalt, when the bulk of the rock is mostly solid. Gabbro is often marketed commercially as black granite and these ultramafic volcanic rocks, with silica contents below 45% are usually classified as komatiites. Agricola applied basalt to the black rock of the Schloßberg at Stolpen. Tholeiitic basalt is relatively rich in silica and poor in sodium, included in this category are most basalts of the ocean floor, most large oceanic islands, and continental flood basalts such as the Columbia River Plateau. Basalt rocks are in some cases classified after their content in High-Ti and Low-Ti varieties. High-Ti and Low-Ti basalts have been distinguished in the Paraná and Etendeka traps and it has greater than 17% alumina and is intermediate in composition between tholeiite and alkali basalt, the relatively alumina-rich composition is based on rocks without phenocrysts of plagioclase. Alkali basalt is relatively poor in silica and rich in sodium and it is silica-undersaturated and may contain feldspathoids, alkali feldspar and phlogopite. Boninite is a form of basalt that is erupted generally in back-arc basins. Ocean island basalt Lunar basalt On Earth, most basalt magmas have formed by melting of the mantle. Basalt commonly erupts on Io, the third largest moon of Jupiter, and has formed on the Moon, Mars, Venus. The crustal portions of oceanic tectonic plates are composed predominantly of basalt, produced from upwelling mantle below, the mineralogy of basalt is characterized by a preponderance of calcic plagioclase feldspar and pyroxene
Basalt
–
Basalt
Basalt
–
Columnar basalt flows in
Yellowstone National Park, USA.
Basalt
–
Columnar basalt at Szent György Hill, Hungary
Basalt
–
Vesicular basalt at
Sunset Crater, Arizona. US quarter for scale.
38.
Chlorite group
–
The chlorites are a group of phyllosilicate minerals. Chlorites can be described by the following four endmembers based on their chemistry via substitution of the four elements in the silicate lattice, Mg, Fe, Ni. Clinochlore, O108 Chamosite, O108 Nimite, O108 Pennantite, 64O108 In addition, zinc, lithium, the great range in composition results in considerable variation in physical, optical, and X-ray properties. Similarly, the range of chemical composition allows chlorite group minerals to exist over a range of temperature and pressure conditions. For this reason chlorite minerals are ubiquitous minerals within low and medium temperature metamorphic rocks, some rocks, hydrothermal rocks. The name chlorite is from the Greek chloros, meaning green, the typical general formula is, 34O102·36. This formula emphasizes the structure of the group, chlorites have a 2,1 sandwich structure, this is often referred to as a talc layer. Unlike other 2,1 clay minerals, a chlorites interlayer space is composed of 6 and this 6 unit is more commonly referred to as the brucite-like layer, due to its closer resemblance to the mineral brucite. Therefore, chlorites structure appears as follows, -t-o-t-brucite-t-o-t-brucite, thats why they are also called 2,1,1 minerals. An older classification divided the chlorites into two subgroups, the orthochlorites and leptochlorites, the terms are seldom used and the ortho prefix is somewhat misleading as the chlorite crystal system is monoclinic and not orthorhombic. Chlorite is commonly found in rocks as an alteration product of mafic minerals such as pyroxene, amphibole. Chlorite is a common mineral associated with ore deposits and commonly occurs with epidote, sericite, adularia. Chlorite is also a metamorphic mineral, usually indicative of low-grade metamorphism. It is the species of the zeolite facies and of lower greenschist facies. It occurs in the quartz, albite, sericite, chlorite, within ultramafic rocks, metamorphism can also produce predominantly clinochlore chlorite in association with talc. Chlorite occurs naturally in a variety of locations and forms, for example, chlorite is found naturally in certain parts of Wales in mineral schists. Chlorite is found in large boulders scattered on the surface on Ring Mountain in Marin County. Clinoclore, pennantite, and chamosite are the most common varieties, several other sub-varieties have been described
Chlorite group
–
Chlorite group
Chlorite group
–
Quartz crystal with chlorite inclusions from
Minas Gerais,
Brazil (size: 4.2 × 3.9 × 3.3 cm)
Chlorite group
–
Chlorite
pseudomorph after
garnet from Michigan (size: 3.5 × 3.1 × 2.7 cm)
Chlorite group
–
Chlorite schist
39.
Epidote
–
Epidote is a calcium aluminium iron sorosilicate mineral. The faces are often deeply striated and crystals are often twinned, many of the characters of the mineral vary with the amount of iron present for instance, the color, the optical constants, and the specific gravity. The color is green, grey, brown or nearly black and it displays strong pleochroism, the pleochroic colors being usually green, yellow and brown. Clinozoisite is green, white or pale rose-red group species containing very little iron, the name, due to Haüy, is derived from the Greek word epidosis which means addition in allusion to one side of the ideal prism being longer than the other. Epidote is an abundant rock-forming mineral, but one of secondary origin and it occurs in marble and schistose rocks of metamorphic origin. It is also a product of alteration of various minerals composing igneous rocks. A rock composed of quartz and epidote is known as epidosite, the perfectly transparent, dark green crystals from the Knappenwand and from Brazil have occasionally been cut as gemstones. Belonging to the same group with epidote are the species piemontite and allanite. Piemontite occurs as small, reddish-black, monoclinic crystals in the mines at San Marcel, near Ivrea in Piedmont. The purple color of the Egyptian porfido rosso antico is due to the presence of this mineral, allanite and dollaseite- have the same general epidote formula and contain metals of the cerium group. The crystallographic and optical characters are similar to those of epidote, the pleochroism is strong with reddish-, yellowish-, and greenish-brown colors. Although not a mineral, allanite is of fairly wide distribution as a primary accessory constituent of many crystalline rocks, gneiss, granite, syenite, rhyolite, andesite. It was first found in the granite of east Greenland and described by Thomas Allan in 1808, allanite is a mineral readily altered by hydration, becoming optically isotropic and amorphous, for this reason several varieties have been distinguished, and many different names applied. Orthite was the name given by Jöns Berzelius in 1818 to a form found as slender prismatic crystals, sometimes a foot in length, at Finbo. Dollaseite is less common, famous from the Ostanmossa mine in the Norberg district of Sweden, dallasite This article incorporates text from a publication now in the public domain, Chisholm, Hugh, ed. article name needed
Epidote
–
Epidote crystals – Deposit topotype
Epidote
–
Epidote from
Alaska
Epidote
–
Sample of dollaseite (dark brown matrix at arrow points) from Sweden
40.
Granite
–
Granite is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granites can be white, pink, or gray in color. The word granite comes from the Latin granum, a grain, in reference to the structure of such a holocrystalline rock. By definition, granite is a rock with at least 20% quartz. The term granitic means granite-like and is applied to granite and a group of igneous rocks with similar textures and slight variations in composition. Occasionally some individual crystals are larger than the groundmass, in case the texture is known as porphyritic. A granitic rock with a texture is known as a granite porphyry. Granitoid is a general, descriptive field term for lighter-colored, coarse-grained igneous rocks, petrographic examination is required for identification of specific types of granitoids. The extrusive igneous rock equivalent of granite is rhyolite, Granite is nearly always massive, hard and tough, and therefore it has gained widespread use throughout human history, and more recently as a construction stone. The average density of granite is between 2.65 and 2.75 g/cm3, its compressive strength usually lies above 200 MPa, and its viscosity near STP is 3–6 •1019 Pa·s. The melting temperature of dry granite at ambient pressure is 1215–1260 °C, it is reduced in the presence of water. Granite has poor primary permeability, but strong secondary permeability, true granite according to modern petrologic convention contains both plagioclase and alkali feldspars. When a granitoid is devoid or nearly devoid of plagioclase, the rock is referred to as alkali feldspar granite, when a granitoid contains less than 10% orthoclase, it is called tonalite, pyroxene and amphibole are common in tonalite. A granite containing both muscovite and biotite micas is called a binary or two-mica granite, two-mica granites are typically high in potassium and low in plagioclase, and are usually S-type granites or A-type granites. A worldwide average of the composition of granite, by weight percent, based on 2485 analyses. Much of it was intruded during the Precambrian age, it is the most abundant basement rock that underlies the relatively thin veneer of the continents. Outcrops of granite tend to form tors and rounded massifs, granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels. Granite often occurs as small, less than 100 km² stock masses
Granite
–
Granite containing
potassium feldspar,
plagioclase feldspar,
quartz, and
biotite and/or
amphibole
Granite
–
Close-up of granite exposed in
Chennai,
India
Granite
–
The
Cheesewring, a granite
tor
Granite
–
A granite peak at
Huangshan, China
41.
Musgrave Block
–
The Musgrave Block is an east-west trending belt of Proterozoic granulite-gneiss basement rocks approximately 500 kilometres long. The Musgrave Block extends from western South Australia into Western Australia, the Musgrave Block is primarily exposed through the actions of the Petermann Orogeny at c. 535-550 Ma, which exhumed the orogenic belt along the Woodroffe Thrust, the Musgrave Block is currently passive geologically, with surficial processes described as residual erosion. The area currently experiences on average less than 150mm of rainfall per annum, the landforms of the area are primarily composed of wide calcrete plains, often covered by Pleistocene Age aeolian deposits of sand dunes, sometimes reworked into ephemeral sheetwash fans. Outcrop is rare, restricted primarily to the rocks of the Giles Complex and several granite domes, gneiss domes. This area is also a distinct province of the larger West Australian Shield. Several Palaeozoic to neoproterozoic sedimentary basins onlap the Musgrave Block, and are exposed mostly around its edges and these were derived from erosion of the Musgrave Block basement during the neoproterozoic to Permian. These include the Proterozoic Amadeus and Officer Basins, the key events in the Musgrave Block are, Protolith formation ~1550 Ma. Formation of crustal rocks of the Birksgate Complex, which are both mafic and felsic in composition, the Kulgera Suite is a widespread, voluminous suite of fractionated amphibole-bearing plagioclase rich tonalite to granodiorites of an I-type affinity. They are dated at ~1200 Ma and are considered to be related to melting of the lower crust during the ~1200 Ma Musgravian Orogeny. The Windburn Suite is considered to be an anorogenic A-type granite suite produced by anatexis of the lower crust at ~1080 to 1050 Ma by the injection of the mafic Giles Complex intrusions. They are in most cases poorly fractionated, biotite-muscovite granites, with little hornblende, a high radiometric count, there are also significant granite caldera complexes, of many hundred square kilometres in area, which intrude the Musgrave Block. These are of the ~1050 Ma age, and are subvolcanic, the whole caldera edifice is tilted to the southwest, which is why the Winburn Granite is exposed along the east and northeast. The Skirmish Hill Caldera is poorly exposed along the margin of the Musgrave Block and consists of granite. It has been seen as a potential source for the Tollu Volcanics. The caldera is truncated on the north by a north-dipping thrust fault and is tilted to the south. Several other prominent gravity and magnetic highs are arranged along the Mugrave Block strike line, one of which was drilled by BHP in the 1990s through 300m of Permian glacial sediments. This caldera is composed of highly tectonised, stretched felsic volcanic rocks, the relationship of the large granite calderas to the 1050-1080 Ma volcanics has been postulated as one in which the granite calderas were the source for the intermediate and felsic volcanic rocks
Musgrave Block
–
Geological interpretation of the West Musgrave Block, Western Australia. 50x50km grid for scale.
Musgrave Block
–
Biogeography
42.
Redox
–
Redox is a chemical reaction in which the oxidation states of atoms are changed. Any such reaction involves both a process and a complementary oxidation process, two key concepts involved with electron transfer processes. Redox reactions include all chemical reactions in which atoms have their oxidation state changed, in general, the chemical species from which the electron is stripped is said to have been oxidized, while the chemical species to which the electron is added is said to have been reduced. It can be explained in terms, Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom. Reduction is the gain of electrons or a decrease in state by a molecule, atom. As an example, during the combustion of wood, oxygen from the air is reduced, the reaction can occur relatively slowly, as in the case of rust, or more quickly, as in the case of fire. Redox is a portmanteau of reduction and oxidation, the word oxidation originally implied reaction with oxygen to form an oxide, since dioxygen was historically the first recognized oxidizing agent. Later, the term was expanded to encompass oxygen-like substances that accomplished parallel chemical reactions, ultimately, the meaning was generalized to include all processes involving loss of electrons. The word reduction originally referred to the loss in weight upon heating a metallic ore such as an oxide to extract the metal. In other words, ore was reduced to metal, antoine Lavoisier showed that this loss of weight was due to the loss of oxygen as a gas. Later, scientists realized that the atom gains electrons in this process. The meaning of reduction then became generalized to all processes involving gain of electrons. Even though reduction seems counter-intuitive when speaking of the gain of electrons, it help to think of reduction as the loss of oxygen. Since electrons are charged, it is also helpful to think of this as reduction in electrical charge. The electrochemist John Bockris has used the words electronation and deelectronation to describe reduction and oxidation processes respectively when they occur at electrodes and these words are analogous to protonation and deprotonation, but they have not been widely adopted by chemists. The term hydrogenation could be used instead of reduction, since hydrogen is the agent in a large number of reactions. But, unlike oxidation, which has been generalized beyond its root element, the word redox was first used in 1928. The processes of oxidation and reduction occur simultaneously and cannot happen independently of one another, the oxidation alone and the reduction alone are each called a half-reaction, because two half-reactions always occur together to form a whole reaction
Redox
–
Rusting iron
Redox
–
A
bonfire
Redox
–
Oxides, such as
iron(III) oxide or
rust, which consists of hydrated
iron(III) oxides Fe 2 O 3 · n H 2 O and
iron(III) oxide-hydroxide (FeO(OH), Fe(OH) 3), form when oxygen combines with other elements
Redox
–
Iron rusting in
pyrite cubes
43.
Cross-bedding
–
In geology, the sedimentary structures known as cross-bedding are the horizontal units that are internally composed of inclined layers. This is a case in geology in which the original depositional layering is tilted, cross-beds or sets are the groups of inclined layers, and the inclined layers are known as cross strata. Cross bedding forms during deposition on the surfaces of bedforms such as ripples and dunes. Examples of these bedforms are ripples, dunes, anti-dunes, sand waves, hummocks, bars, Cross-bedding is widespread in many environments. Environments in which movement is fast enough and deep enough to develop large-scale bed forms fall into three natural groupings, rivers, tide-dominated coastal and marine settings. Cross beds can tell much about what an area was like in ancient times. The direction the beds are dipping indicates paleocurrent, the direction of sediment transport. The type and condition of sediments can tell geologists the type of environment, studying modern analogs allows geologists to draw conclusions about ancient environments. Paleocurrent can be determined by seeing a cross-section of a set of cross-beds, however, to get a true reading, the axis of the beds must be visible. It is also difficult to distinguish between the beds of a dune and the cross beds of an antidune. This could lead to misinterpretation since dunes dip downstream while antidunes dip upstream, the direction of motion of the cross-beds can show ancient flow or wind directions. The foresets are deposited at the angle of repose, so geologists are able to measure dip direction of the cross-bedded sediments, however, most cross-beds are not tabular, they are troughs. Since troughs can give a 180 degree variation of the dip of foresets, in this case, true paleocurrent direction is determined by the axis of the trough. Paleocurrent direction is important in reconstructing past climate and drainage patterns, sand dunes preserve the prevalent wind directions, Cross-bedding is formed by the downstream migration of bedforms such as ripples or dunes in a flowing fluid. The fluid flow causes sand grains to saltate up the side of the bedform. At this point, the crest of granular material has grown too large and will be overcome by the force of the depositing fluid, repeated avalanches will eventually form the sedimentary structure known as cross-bedding, with the structure dipping in the direction of the paleocurrent. The angle and direction of cross-beds are generally fairly consistent, individual cross-beds can range in thickness from just a few tens of centimeters, up to hundreds of feet or more depending upon the depositional environment and the size of the bedform. Cross-bedding can form in any environment in which a fluid flows over a bed with mobile material and it is most common in stream deposits, tidal areas, and in aeolian dunes
Cross-bedding
–
Crossbedding of
sandstone near Mt. Carmel road,
Zion Canyon, indicating wind action and sand
dune formation had occurred prior to formation of the rock.
Cross-bedding
–
Cross-bedding in a sandstone dome in the
Canyons of the Escalante.
Cross-bedding
–
Sand dune cross-beds can be large, such as in the
Jurassic -age
erg deposits of the
Navajo Sandstone in
Canyonlands National Park.
Cross-bedding
–
Close up of cross-bedding and
scour,
Logan Formation, Ohio
44.
Ripple marks
–
In geology, ripple marks are sedimentary structures and indicate agitation by water or wind. Current ripple marks, unidirectional ripples, or asymmetrical ripple marks are asymmetrical in profile, with a gentle up-current slope, the down-current slope is the angle of repose, which depends on the shape of the sediment. These commonly form in fluvial and aeolian depositional environments, and are a signifier of the part of the Lower Flow Regime. Ripple cross-laminae forms when deposition takes place during migration of current or wave ripples, a series of cross-laminae are produced by superimposing migrating ripples. The ripples form lateral to one another, such that the crests of vertically succeeding laminae are out of phase and this process results in cross-bedded units that have the general appearance of waves in outcrop sections cut normal to the wave crests. In sections with other orientations, the laminae may appear horizontal or trough-shaped, depending upon the orientation, scientists suggest current drag, or the slowing of current velocity, during deposition is responsible for ripple cross-laminae. In most present-day streams, ripples will not form in sediment larger than coarse sand, therefore, the stream beds of sand-bed streams are dominated by current ripples, while gravel-bed streams do not contain bedforms. The internal structure of ripples is a base of sand with coarse grains deposited on top since the size distribution of sand grains correlates to the size of the ripples. This occurs because the fine grains continue to move while the coarse grains accumulate, fluid drag ripples Also known as aerodynamic ripples, these are formed with fine, well-sorted grain particles accompanied by high velocity winds which result in long, flat ripples. The flat ripples are formed by long saltation paths taken by grains in suspension, crest The point on a wave with the maximum value or height. It is the location at the peak of the cycle as shown in picture to the right. Trough The opposite of a crest, so the value or height in a wave. It is the location at the very lowest point of a wave cycle also shown in picture to right, lee The lee side has a steeper slope than the stoss. The lee is always on the side of the ripple. The current flows down the lee side, stoss The stoss is the side of a wave or ripple that has a gentle slope versus a steeper slope. Current always flows up the side and down the lee side. This can be used to determine current flow during the time of ripple formation, capillary wave Giant current ripples Water on Mars - sedimentary ripple marks show indirect evidence of ancient water flows on our neighbor planet Easterbrook, Don J. Surface processes and landforms. Upper Saddle River, N. J, Prentice Hall,1999, greeley, Ronald, and James D. Iversen
Ripple marks
–
Ancient wave ripple marks in
sandstone,
Moenkopi Formation,
Capitol Reef National Park,
Utah
Ripple marks
–
Wave/symmetrical ripple, Nomgon, Mongolia
Ripple marks
–
Cross-section through asymmetric climbing ripples, seen in the
Zanskar Gorge,
Ladakh, NW Indian
Himalaya. Ripples climb when sediment fluxes in the flow are very high.
Ripple marks
–
Ripple marks in
Cretaceous Dakota Formation, east side of
Dinosaur Ridge. Scale bar on notebook is 10 cm.
45.
Fluvial
–
Fluvial is a term used in geography and geology to refer to the processes associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, fluvial processes include the motion of sediment and erosion or deposition on the river bed. Erosion by moving water can happen in two ways, firstly, the movement of water across the bed exerts a shear stress directly onto the bed. However, if the river carries significant quantities of sediment, this material can act as tools to enhance wear of the bed, at the same time the fragments themselves are ground down, becoming smaller and more rounded. Sediment in rivers is transported as either bedload or suspended load, there is also a component carried as dissolved material. For each grain size there is a velocity at which the grains start to move. However the grains will continue to be transported even if the velocity falls below the entrainment velocity due to the friction between the grains and the river bed. Eventually the velocity will fall low enough for the grains to be deposited and this is shown by the Hjulstrøm curve. A river is continually picking up and dropping solid particles of rock, where the river flow is fast, more particles are picked up than dropped. Where the river flow is slow, more particles are dropped than picked up, areas where more particles are dropped are called alluvial or flood plains, and the dropped particles are called alluvium. Even small streams make alluvial deposits, but it is in the plains and deltas of large rivers that large. The amount of matter carried by a river is enormous. The names of rivers derive from the color that the transported matter gives the water. For example, the Huang He in China is literally translated Yellow River, and it has been estimated that the Mississippi River annually carries 406 million tons of sediment to the sea, the Yellow River 796 million tons, and the Po River in Italy 67 million tons. Lacustrine - of or relating to a lake maritime - of or relating the sea oceanic - of or relating to an ocean palustrine - of or relating to a marsh
Fluvial
–
Deep, eroding glaciofluvial deposits alongside the
Matanuska River,
Alaska
46.
Alluvial fan
–
An alluvial fan is a fan- or cone-shaped deposit of sediment crossed and built up by streams. If a fan is built up by debris flows it is called a debris cone or colluvial fan. These flows come from a point source at the apex of the fan. Fans are typically found where a canyon draining from mountainous terrain emerges out onto a flatter plain, a convergence of neighboring alluvial fans into a single apron of deposits against a slope is called a bajada, or compound alluvial fan. As a streams gradient decreases, it drops coarse-grained material and this reduces the capacity of the channel and forces it to change direction and gradually build up a slightly mounded or shallow conical fan shape. The deposits are poorly sorted. There will be iso-transport energy lines forming concentric arcs about the point at the apex of the fan. Thus the material will tend to be deposited equally about these lines, Alluvial fans are often found in desert areas subject to periodic flash floods from nearby thunderstorms in local hills. The typical watercourse in an arid climate has a large, funnel-shaped basin at the top, leading to a narrow defile, multiple braided streams are usually present and active during water flows. Phreatophytes are plants that are concentrated at the base of alluvial fans. They have long tap roots 30 to 50 feet to water that has seeped through the fan and hit an impermeable layer, sometimes collecting in springs. These stands of shrubs cling to the soil at their bases, Alluvial fans also develop in wetter climates. Along the upper Koshi tributaries, tectonic forces elevate the Himalayas several millimeters annually, uplift is approximately in equilibrium with erosion, so the river annually carries some 100 million cubic meters of sediment as it exits the mountains. Deposition of this magnitude over millions of years is more than sufficient to account for the megafan, despite overpopulation on the plains, this bhabar zone is highly malarial and has remained largely uninhabited. In North America, streams flowing into Californias Central Valley have deposited smaller, such as that of the Kings River flowing out of the Sierra Nevada creates a low divide, turning the south end of the San Joaquin Valley into an endorheic basin without a connection to the ocean. Alluvial fans are subject to flooding and can be more dangerous than the upstream canyons that feed them. Their slightly convex perpendicular surfaces cause water to spread widely until there is no zone of refuge, if the gradient is steep, active transport of materials down the fan creates a moving substrate that is inhospitable to travel on foot or wheels. But as the gradient diminishes downslope, water comes down from above faster than it can flow away downstream, in the case of the Koshi River, the huge sediment load and megafans slightly convex transverse surface conspire against engineering efforts to contain peak flows inside manmade embankments
Alluvial fan
–
A vast (60 km long) alluvial fan blossoms across the desolate
landscape between the
Kunlun and
Altun mountain ranges that form the southern border of the
Taklamakan Desert in
Xinjiang. The left side is the active part of the fan, and appears blue from
water flowing in the many small
streams
Alluvial fan
–
Alluvial fan in
Death Valley
Alluvial fan
–
Alluvial fan above
Lake Louise,
Alberta, Canada.
Alluvial fan
–
Ground-level view of a large alluvial fan in
Death Valley
47.
Mount Conner
–
It reaches to 859 metres above sea level and to 300 metres above ground level. Mount Conner is a flat-topped and horseshoe-shaped inselberg/mesa, part of the same vast rocky substrate thought to be beneath Uluru/Ayers Rock and it can easily be confused with Uluru, since it can be seen from the road to Uluru and Kata Tjuta, when approaching from Alice Springs. It was named Mount Conner by William Gosse in 1873 after South Australian politician M. L. Conner, attila is close to the site of Kungkarangkalpa, the Seven Sisters Dreaming. Mt Conner consists of conglomerates, sandstones, siltstones, and mudstones of the Late Ediacaran–Early Cambrian Winnall beds, the Winnall beds form the upper part of Mt Conner. The summit consists of grey to coarse-grained sandstone with layers and minor beds of pebble conglomerate. The Winnall beds that underlie this scarp is a unit composed of dark brown micaceous siltstone, mudstone. The lower part of Mt. Conner consists of planar and trough cross-bedded, medium to coarse-grained, grey-brown sandstones, dark brown siltstones, the upper part of the Inindia beds are fluvial deposits. The sides of Mt Conner are also blanketed by scree and its top is blanketed by colluvium, the base of Mt Conner is surrounded by alluvium. The summit of Mt Conner, along with the summits of low domes in the Kata Tjuta complex and it is considered to a classic example of an inselberg created by erosion of surrounding strata. A Guide to the Geology and Landforms of Central Australia, Alice Springs, Northern Territory Geological Survey
Mount Conner
–
Mount Conner seen from the road to Uluru
Mount Conner
–
Landscape with Mt Conner
48.
Strike and dip
–
Strike and dip refer to the orientation or attitude of a geologic feature. The strike line of a bed, fault, or other feature, is a line representing the intersection of that feature with a horizontal plane. On a geologic map, this is represented with a straight line segment oriented parallel to the strike line. One technique is to take the strike so the dip is 90° to the right of the strike. The map symbol is a line attached and at right angles to the strike symbol pointing in the direction which the planar surface is dipping down. The angle of dip is generally included on a map without the degree sign. Beds that are dipping vertically are shown with the dip symbol on both sides of the strike, and beds that are flat are shown like the vertical beds, both vertical and flat beds do not have a number written with them. Another way of representing strike and dip is by dip and dip direction, the dip direction is the azimuth of the direction the dip as projected to the horizontal, which is 90° off the strike angle. For example, a bed dipping 30° to the South, would have an East-West strike, but would be written as 30/180 using the dip and dip direction method. Strike and dip are determined in the field with a compass, compass-clinometers which measure dip and dip direction in a single operation are often called stratum or Klar compasses after a German professor. Smartphone apps are also now available, that use of the internal accelerometer to provide orientation measurements. Combined with the GPS functionality of devices, this allows readings to be recorded. Any planar feature can be described by strike and dip and this includes sedimentary bedding, faults and fractures, cuestas, igneous dikes and sills, metamorphic foliation and any other planar feature in the Earth. Linear features are measured very similar methods, where plunge is the dip angle. Apparent dip is the name of any dip measured in a plane that is not perpendicular to the strike line. True dip can be calculated from apparent dip using trigonometry if you know the strike, Geologic cross sections use apparent dip when they are drawn at some angle not perpendicular to strike. New York, J. Wiley and Sons, tarbuck, Edward J. Lutgens, Frederick K. 0-13-092025-8 Earth, An Introduction to Physical Geology. Upper Saddle River, N. J. Pearson Prentice Hall, digital Cartographic Standard for Geologic Map Symbolization
Strike and dip
–
A standard
Brunton compass, used commonly by geologists for strike and dip measurements
Strike and dip
–
Stratum compass to measure dip and dip direction in one step
Strike and dip
–
Strike line and dip of a plane describing attitude relative to a horizontal plane and a vertical plane perpendicular to the strike line
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